He appears on the first day of the V-Wave season, when he shoots down from the sky with his V-Wheel. He lands next to the V-Wavecast (and almost on the player, their partner, Gurdurr, his Timburr apprentices, Quagsire, and Virizion). When they come to Victini, he poses and yells, "V-Wheeeeeeeeeeeeeeeel!" Virizion tells the others that Victini realized the bad effects of the V-Wave and created the V-Wheel. Whenever the time comes to mention the V-Wheel, Victini will pose and shout, "V-Wheeeeeeeeeeeeeeeel!" Virizion tells him that some Pokémon might get annoyed, so he should probably stop. Victini replies, "Okay. I'll stop. Maybe. V-Wheeeeeeeeeeeeeeeel!"
Victini does not just run the V-Wheel; he will also show the V-Wavecast.
After Emolga switches places with Dunsparce in the Magnagate and it closes, Victini tries to console the crying Pokémon by saying, "Don't worry! You can spin the V-Wheel!"
Victini appears in Café Connection sometimes. Victini is connected to a Glaceon.
Spoilers end here.
Victini at the V-Wheel
A spinner with five spaces, the V-Wheel is Victini's pride and joy. One of the five spaces has his face drawn on it. Once a day, the player can spin the V-Wheel, and if a drawing of Victini's face is landed on, the player can change the V-Wave to whichever type they would like; otherwise, the V-Wave will be unchanged for that day. For the following amounts of Poké, the player can add images of his face to additional spaces on the V-Wheel.
The reason why the fifth face to the V-Wheel costs 7777 instead of ending in two zeros like the other costs, is most likely due to the fact that in Japan, the number seven is considered as a lucky number, reflecting the fact that with five faces, the V-Wheel is sure to land on one of them.
For more information on this Pokémon's species, see Victini.