Korrina first appears on Route 5, when one of her Lucario comes up to the player while she is doing some special training. She notes about how Lucario has taken a liking to the player's aura, then introduces herself to the player as the Shalour City Gym Leader. She then appears in Geosenge Town, where she challenges the player to a battle with her two Lucario.
After arriving in Shalour City, Korrina can be found in the Tower of Mastery with her grandfather Gurkinn, the Mega Evolution guru. Once the player wins the battle for the Mega Ring against their rival, Korrina will go to her Gym for a battle.
After battling her at the Gym, she will immediately invite the player to a rematch atop the Tower of Mastery. There, Korrina gives the player the Mega Ring. After that, the Lucario that had become close to the player temporarily joins their team, and the two have a one-on-one battle, using just their Lucario, both holding a Lucarionite. Win or lose, the player has the option of getting the Lucario that joined him/her for the battle.
Once the player obtains rank of Marquis/Marchioness at the Battle Chateau, Korrina and the other Gym Leaders will be able to be battled there for rematches. There, Korrina will possess the rank of Marchioness.
"Sorry about that! Are you OK? I was just doing some special training with my Lucario when all of a sudden it dashed off... Hey, Lucario! What's going on with you? Did you get drawn in by this boy's/girl's aura or something?"
"Huh. Well, it seems Lucario likes you!"
Regardless of choice: "See, Lucario can read people's auras. I guess something in your aura has made this one take a liking to a stranger! This Lucario is always getting worked up in battle with my other one. Maybe it's just been waiting for a Trainer to appear who's strong enough to challenge it... Oops, sorry! I was on such a roll, I forgot to even introduce myself! I'm Korrina, the Shalour CityGym Leader. If you're collecting Gym Badges, I'm sure we'll be battling sooner or later! I'll be looking forward to it. I hope you know how to roll with the punches!"
"I'm not exactly sure, but I think Lucario is saying it wants to battle with you. Would you battle with us? So, I have two Lucario... But do you know which is the one that has taken a shine to you?"
Upon being defeated
"Wh-what?! Not even my ultra-powerful Lucario duo could stand up to you?!"
After being defeated
"OK! Now I get it! I see why Lucario likes you so much! So! Do you remember that I'm the Gym Leader in Shalour City? Once you get past the cave just beyond here, you'll be there, so stop by and say hello!"
"Hey there! So you made it to Shalour City! Lucario is in its Poké Ball, but it's really happy to see you! Well, we should go see what's going on, too!"
During the conversation about Mega Evolution
"Exactly! And it's likely that Pokémon evolve in a lot of other ways as well! But Mega Evolution is an Evolution that transcends all other Evolution!"
"Yep! Exactly right! But not all Pokémon have a Mega Evolution."
"Yes... Mega Evolution is a special kind of Evolution. That said, we still know very little about it. What we know now is that it requires special items. And the most important element is the trust between Pokémon and Trainer."
"There may be winners and losers in a Pokémon battle. But I really thought you two and your Pokémon were all winners! Mega Evolution is nothing more than just one way to make Pokémon stronger. There are many Trainers who bring out the strength of their Pokémon without Mega Evolution."
"Pokémon need a Mega Stone! And Pokémon Trainers need the Mega Ring! Well, my mysterious Trainer, my Lucario may have taken a shine to you, but now I must test you to see if you're ready to challenge the Mega Evolution successor! I'll be waiting for you at the Gym! Oh, the rest of your friends should come challenge me at the Gym, too!"
"Haha, I'm just messing around with you! I know, you're rollin' in the aisles, right? I already know you're a strong Trainer, so let's get this show on the road!"
Upon being defeated
"How could it be?!"
After being defeated
"Oh! I have been defeated! Alack, alay! Lady Korrina gave a terrible display! This is it. I must give up my title and admit that your strength far exceeds-- Just teasing! But here's your Badge. Boy, you'll be rolling in 'em soon!"
"If you've got a Rumble Badge, then you can trade Pokémon up to Lv. 50 with your friends and they'll be ready to roll! They'll love you, all right! And you'll be able to roll over waves using the HMSurf, even outside battle! And here, why don't you take this TM? I've really been on a roll with it myself!"
"Power-Up Punch does just what it says on the box! The more that you use it, the tougher your fists get. Keep using it. Your Attack will go through the roof! Look... I do have to apologize. You'll have to make it up to the top of the Tower of Mastery if you want the Mega Ring. I'm sorry for sending you this way and that. I swear, I'm not giving you the runaround! You've done great rolling with the punches. So great that I'd like to ask you a favor... Battle me again, won't you? But this time, it won't be just another Gym Battle... I want a battle between equals! As two Trainers who can use Mega Evolution! I'll be waiting for you with Lucario at the top of the Tower of Mastery!"
Tower of Mastery
Before giving the Mega Ring
"I really love this place! When I'm here with my Pokémon, looking at the wide-open sky above, all my worries disappear, and I feel like I can do anything!"
"Thanks for coming all the way up here. It was decided that this must be the place where the Mega Ring is handed over. Something about making sure we never forget to set our sights as high as the sky. And here it is--your very own Mega Ring! It's in the shape of a bracelet, so it's super easy to wear!"
"Give your Pokémon the right Mega Stone, and try battling with it! Your Pokémon will surely answer the call of the Mega Ring!"
"Hmm? Lucario, what's wrong?"
"Lucario, are you sure? You want to battle alongside that Trainer?"
"I don't know what to say... I'm a bit shocked that some traveling Trainer seems to have a stronger bond with you than I do... Haha! Well, he/she must be something special! So, whaddya say, Trainer? Will you and Lucario battle against me and my Lucario? A Lucario-on-Lucario battle! It will be nothing short of riveting. They both have Lucarionite in hand! How about we get this show on the road?"
No: "Oh, come on! Both are at the ready with Lucarionite! Let's battle!"
Yes: "I can feel Lucario's passion. Perhaps it's just that it doesn't want to lose to the other Lucario, but it may be that it's just on the same wavelength as you..."
"Let's give it all we've got!"
Upon being defeated
"What an incredible bond you have! What amazing power!"
After being defeated
If the player did not Mega Evolve Lucario during the battle: "I really want you to give Lucario a chance to see what Mega Evolution is like!"
"What an explosive battle! I could tell that both Mega Lucario didn't hold anything back! With strong bonds like that, you shouldn't have any trouble triggering your Pokémon's Mega Evolution!"
"I think it would be best if you took that Lucario along with you on your journey. It's quite apparent that you two make a truly incredible team!"
If the player refuses to take Lucario
"Really? I thought the two of you would have made a great team..."
After accepting or refusing to take Lucario
"As long as Pokémon and Trainers have the kindness to care for each other and give each other courage, the world will be full of smiles!"
If talked to again
"What an explosive battle! I could tell that both Mega Lucario didn't hold anything back! With strong bonds like that, you shouldn't have any trouble triggering your Pokémon's Mega Evolution! As long as Pokémon and Trainers have the kindness to care for each other and give each other courage, the world will be full of smiles!"
"Time for the new-and-improved Lady Korrina's big appearance!"
Upon being defeated
"It's your very being that allows your Pokémon to evolve!"
After being defeated
If giving the player an item: "Oh well, I can roll with the punches. Take this. I award it to you, good sir/fair lady."
"Oh! Defeat! Alack, alay!"
April: "Hello! It's time for Gym Freaks, your source for the hottest news about hot Gym Leaders in Kalos. So... I'm now in front of the Shalour City Gym! ... Eeek. Korrina has arrived! She's cute! So cute! The way she dresses up in costume-like clothing makes my heart go crazy! Lately, Korrina has been in the PR Video Studio! Following two years of planning and another year of shooting, her highly anticipated new PR Video is scheduled for release at the end of next year! Oh... She went inside the Gym... That's all for the on-site report. Good-bye for now, everyone."
April: "Hello! It's time for Gym Freaks, your source for the hottest news about hot Gym Leaders in Kalos. So... I'm now in front of the Shalour City Gym! ... Eeek. Korrina has arrived! She's cute! So cute! The way she dresses up in costumes make my heart beat pit-a-pat! Her legs are so magnificent that her axe-kick move can shatter cave rocks into pieces! If I were her, I wouldn't need the HM. Oh... She went inside the Gym... That's all for the on-site report. Good-bye for now, everyone."
Korrina debuted in Mega Revelations!. She appeared before Ash and his friends, aiming to claim her 99th successive victory, eagerly challenging Ash to a battle. In the end, her Lucario easily defeated Ash's Pikachu, and the group decided to have a lunch together, during which Bonnie noticed Korrina's Key Stone. She revealed that she had received it from her grandfather. However, she was still lacking the Mega Stone to Mega Evolve her Lucario. After the group had saved Pikachu and Lucario from Team Rocket, Ash and his friends decided to join Korrina on her hunt for Lucarionite.
In The Cave of Trials!, Korrina, along with Ash and his friends, arrived in Geosenge Town. There, they met a photographer called McGinty, who gave them a hint of going to a nearby mountain. On the mountain, the group discovered a cave, where the Lucarionite was hidden. Protecting the Mega Stone, however, was a Blaziken, whom Korrina had to battle. Due to Blaziken having a type advantage over Lucario, Korrina was initially losing, but thanks to Ash and friends' encouragements, Korrina and Lucario were able to rise from the brink of defeat and immobilize Blaziken with Bone Rush. Just when Lucario was about to finish the battle, Korrina's grandfather, Gurkinn, came out of the shadows, admitting his defeat and allowing Korrina to take the Lucarionite. With the proper Mega Stone finally in her hands, Korrina started her Lucario's very first Mega Evolution.
In The Aura Storm!, after Lucario's first Mega Evolution, Korrina agreed to have a battle with Ash and Pikachu to test her Mega Evolved Pokémon's powers. However, during the battle, Lucario lost control, and it was only stopped from attacking Ash along with Pikachu by Gurkinn's own Lucario. Gurkinn explained that Lucario couldn't control its increased Aura powers after Mega Evolving, which was why it went berserk. Korrina then had another battle with her Lucario, this time against Gurkinn's own Mega Lucario. However, Korrina's Lucario lost control of itself again soon after Mega Evolving, and Gurkinn won the battle. Afterwards, Gurkinn sent Korrina and Lucario to Pomace Mountain to get help from a Mega Evolution Trainer.
In The Bonds of Mega Evolution!, Korrina arrived at Mabel's manor on Pomace Mountain. Mabel challenged Korrina and Lucario to battle her Mega Mawile, but Lucario was defeated when it lost control of its Mega Evolved form. Mabel then had Korrina and Lucario arrange flowers together so they could bring each other's differing viewpoints together and transform it into strength, with their hearts acting as one. When Team Rocket stole Pikachu and Mawile, Mega Lucario was used to rescue them, but it went out of control again. However, the dilemma was solved when Korrina convinced it to listen to her and control its Aura. Lucario subsequently freed Pikachu and Mawile by knocking Pumpkaboo into Team Rocket's balloon with Bone Rush. In the process, Lucario learnt a new move, Aura Sphere, and finished the fight by using it on Team Rocket's balloon. Although Ash and Korrina were both heading toward the Shalour Gym for their Gym battle, Ash said he needed to train his Pokémon more, and Korrina split off from the group.
In Origins of Mega Evolution!, Korrina met up with Ash and his friends when they arrived in Shalour City. She reappeared in the following episode, where she and Ash had their Gym battle at the Shalour Gym, located inside the Tower of Mastery. At first, Ash attempted to copy Tierno's dancing battle strategies from the Pokémon Summer Camp, but wasn't successful. After switching back to his own style of battling, Ash proceeded to defeat both Korrina's Mienfoo and Machoke with Hawlucha and Fletchinder, respectively. Determined to still win, Korrina sent out Lucario and immediately Mega Evolved it. With this power boost, Lucario was easily able to beat Fletchinder and Hawlucha, leaving Ash with just his last Pokémon, Pikachu. Mega Lucario's overwhelming power gave Pikachu a lot of trouble, but eventually, after a fierce exchange of attacks, Pikachu was able to defeat Mega Lucario and win the match for Ash, thus earning him the Rumble Badge. She then told him that the next Gym was in Coumarine City, and that the next Gym Leader was eccentric, but she believed Ash could help sort him out.
Mienfoo was used as Korrina's first Pokémon during her Gym battle with Ash. It battled Ash's Hawlucha. Though it dealt lots of damage on Hawlucha due to Ash using Tierno's strategies instead of his own, it was later defeated with a Flying Press.
Machoke was used as Korrina's second Pokémon during her Gym battle with Ash. It battled Ash's Fletchinder, and although it was very speedy and had powerful attacks, it was defeated with a Flame Charge.
Korrina first appears in Santalune City, where she helps X and his friends face Celosia of Team Flare to retrieve X's stolen Kangaskhanite. Using her Mega Glove, Korrina Mega Evolves her Lucario into Mega Lucario and sends it out to battle. After X retrieves the Kangaskhanite, he uses it to evolve Li'l Kanga into Mega Kangaskhan and teams up with Lucario. Together, they defeat Celosia, forcing her to retreat since she knows that she's outmatched against two Mega-Evolved Pokémon. Later, Korrina meets up with X's friends and gives Tierno a pair of Roller Skates. When X states that he doesn't think it's important to have a successor ceremony for his Mega Ring, Korrina states that she refuses to acknowledge him as a successor. She questions her grandfather's decision to give X the Mega Ring and angrily storms off.
Korrina goes back to Shalour City, where she angrily attacks her grandfather for giving X a Mega Ring and demands to know why he decided to do it. Before Gurkinn can give a proper answer, they are attacked by a Trevenant. Korrina immediately goes to battle it, but soon realizes that the attack is only a distraction to separate her from her grandfather. She looks outside to see Gurkinn being attacked by Essentia. After escaping from the Trevenant, Korrina skates down to the bottom floor to help Gurkinn. When Gurkinn realizes that Essentia is attempting to steal the tower by covering it in Trevenant's vines, he tells Korrina that they need to activate the Tower of Mastery's self destruct switch and protect the secrets of Mega Evolution. Although reluctant, Korrina agrees and helps her grandfather destroy the tower.
Afterward, the two go into hiding. After being awoken from a dream of her training days, Korrina meets Diantha, another one of the students who received a Key Stone from Gurkinn. They go and meet up with Gurkinn, only to find him being attacked by Team Flare Admin Chalmers. They defeat Chalmers and save Gurkinn with their Mega-Evolved Pokémon. Diantha decides that they should go and find the Legendary Pokémon Yveltal's cocoon form since Team Flare has already secured the tree form of Xerneas. Further on in their journey, Korrina and the others find a wild Diancie being attacked by a thief. They manage to defeat the thief with their Mega-Evolved Pokémon, but Diancie is forced to find a new home. As it thanks them and leaves, Gurkinn reveals that Diancie is capable of Mega Evolution.
Later, the group travels to the location of where Team Flare is preparing to take Xerneas's tree using a group of mind-controlled citizens from Vaniville Town. They find X and his friends there having been defeated by Celosia in an attempt to rescue the townspeople. Before Celosia can finish X off, he is saved by Korrina, Gurkinn, and Diantha, who use their Mega-Evolved team to battle Celosia and Essentia. While Gurkinn remains with X and his friends and Diantha is attacked by Malva, Korrina goes off alone to stop Celosia from taking Xerneas away to Team Flare's base. As the two battle, Korrina declares that she will not let Team Flare continue their takeover of Kalos, to which Celosia states that Team Flare has already taken it over and they just no longer need to keep their actions a secret. Korrina eventually defeats Celosia by having her Lucario throw Celosia's Aegislash at its Trainer, defeating the both of them at the same while also knocking Lucario out from exhaustion. Korrina confidently proclaims that she had won the battle, but fails to notice the Honedge lurking behind her. As she turns around, the Honedge attacks Korrina, sending her to fall onto the ground. X and his friends later find Korrina lying on the ground unconscious with the Key Stone in her Mega Glove removed.
Afterwards, Korrina was taken to a hospital in Laverre City to recuperate alongside the townspeople that were captured by Team Flare. Though her injuries weren't serious, the doctors speculated that the loss of her Key Stone would leave Korrina with some psychological trauma.
Three months after Team Flare's defeat, X was asked by Korrina to come to Shalour City to become an official Mega Evolution Successor.
Lucario is Korrina's only known Pokémon that she had ever since he was a Riolu. He was first seen with his Trainer in Santalune City, where he Mega Evolved into Mega Lucario to battle against Celosia of Team Flare. With his Aura, he prevented Celosia's Aegislash from controlling X and his friends' minds. Together with Kanga and Li'l Kanga, Lucario defeated Celosia, forcing her to escape.
Korrina was introduced as a Supporter card in the Pokémon Trading Card Game during the English XY Series (the Japanese XY Era). It was first released in the Japanese Rising Fist expansion before debuting in English in the Furious Fists expansion, with an illustration based on the Yusuke Ohmura artwork of the character. It was also released as a Full Art card in both expansions, with an illustration also by Yusuke Ohmura. Korrina allows the player to add both a Pokémon and an Item card from their deck to their hands before shuffling the deck.
Korrina's Japanese Leader title is エボリューション ファイター！.