You know when you rile your dog up on purpose so he’s hyper and ready to play? Same thing except for battle. Lance is his own Pokémon’s hype man. That’s what I like to imagine he does that hands up/holding his cape up pose for anyways.
Bonus while I was trying to imagine this happening pre-match before Leon:
[charizard voice] why cant we have that
(btw if you’re wondering how I knew Lance’s Gyrados was a male, female shiny Gyrados keep their white whiskers while the male’s turns red. Also most first gen Pokémon trainers had Pokémon of the same gender)
teamgayotix