Serena is a girl living in Vaniville Town with her friends Calem, Tierno, Trevor, and Shauna. She recently moved into Vaniville Town. Her mom owns a Rhyhorn and Fletchling, the latter of which wakes Serena up at the start of the game.
As a non-playable character
Serena is a young girl who lives in Vaniville Town when the protagonist moves into town. Serena is the main rival of the character, choosing the starter Pokémon which is super-effective to the player's. She is also the character who teaches the player and Shauna how to catch a Pokémon, catching a Bunnelby with the use of her Fletchling. Soon after, she can be seen in Santalune Forest with the other friends.
Serena is the child of two prominent Pokémon battlers, and is seen as one of the two best battlers of the group of friends, alongside the protagonist.
The next time Serena battles the player is in front of the Coumarine Gym.
When the group of friends meets up and decides to go to the haunted area in Route 14, Serena is the only one of the friends to not go to the house, claiming that she has to train. She then helps the player defeat Team Flare at the Poké Ball Factory.
The next time Serena battles the player is in front of the Anistar Gym. After the player defeats the gym, she will ask for a rematch, but cancels her challenge after Lysandre announces his plan of eradicating all life forms not a part of Team Flare. She then helps the player defeat Team Flare get to the legendary Pokémon and defeat Team Flare for good.
As the player traverses Victory Road, Serena appears by a derelict altar and demands one last battle before their final challenge.
After the player enters the Hall of Fame and battles at the Battle Maison, Serena can be battled in Kiloude City, at which point she has obtained a Mega Ring of her own. When defeated for the first time here, she will give the player an Absolite and tell the player to meet Professor Sycamore in Anistar City. She can be battled at Kiloude City once per day.
Pokémon
Catching tutorial
Serena has another Pokémon besides her Fletchling, likely her starter, as noted by having two party slots filled during the tutorial.
Serena appears alongside Calem as a trophy in the 3DS version. They are both simply referred to as Pokémon Trainer (Pokémon X & Y). Also, one of Jigglypuff's alternate costumes has it wearing Serena's hat.
Trophy information
NA:We suppose it's possible you've missed out up till now, so let us explain: in Pokémon, you set out from your hometown on a Pokémon journey, catching Pokémon and fighting battles with them. In Pokémon X and Pokémon Y, you reach the next town and find yourself embroiled in a tale of... No, wait–no spoilers!
PAL:If you've been living under a rock for some years now, let us explain. In Pokémon, you start from your home town on your own Pokémon journey, catching Pokémon and fighting battles with them. In Pokémon X and Pokémon Y, you reach the next town and find yourself embroiled in a tale of... Well, we won't spoil it for you.
Serena appeared in The Visionary as Calem's rival. She and Shauna joined Calem after he had defeated Lysandre at the Team Flare Secret HQ. When Lysandre started firing the ultimate weapon, the three young Trainers fled the HQ together. Afterwards, they witnessed the weapon sinking back into the ground.
The character Y is modeled after Serena. She is an aspiring Sky Trainer, having chosen to become one to oppose people's expectations of her following in her mother's footsteps as a Rhyhorn racer. She rotates through several different hairstyles throughout the X & Y arc.
Serena was introduced as a Supporter card in the Pokémon Trading Card Game during the English Sword & Shield Series (the Japanese Sword & Shield Era). It was first released in the Japanese Incandescent Arcana subset before debuting in English in the Silver Tempest expansion, with artwork by Ken Sugimori. A Full Art ultra rare and a rainbow rare version of the card with artwork by Megumi Mizutani were included in these expansions as well. The card allows the player to either discard up to three cards from their hand, then draw cards until they have five cards in hand, or switch in one of their opponent's Benched Pokémon V to the Active Spot.
Serena is also featured on the Trainer Gallery holo rare print of Braixen from the Silver Tempest Trainer Gallery.
Trivia
Pre-release media referred to Serena as "Yvonne" (Japanese: ワイY). This name would become the name of Serena's counterpart in Pokémon Adventures.