After your first win in this Arena, you felt pretty confident in your strategy. Belle had all advantages on her side, being a Thunder-Type and equipped with powerful set-up moves. Arena-Boss Molly recognized this, and she declared, she would take you more seriously now.
You nodded firmly at that. "Great. Then, one more thing: I´m also a little experienced with your Crest Power. So there is no need for more cantrips like aging up or down mid-battle. Especially the last thing. Turning your Beastie into an infant just to be slapped around was rude, you know?"
Molly´s eyes widened a little by this. An Arena-Boss being lectured, that was no small thing. "A Trainer has to know when to cut their losses", she replied dryly, "and when to stall a brawl as well."
As she spoke these words, the electrical field which Belle had created vanished, having reached it´s expiry date. Molly smiled. "My, have we talked too much already? - Not that it would have had much effect on our next brawl."
You smirked. "We will make a new one."
"Well, go ahead." Molly took her next BeastCube. "Never interrupt your enemy when he is making a mistake!" She summoned her BeastMon. "Go, Gamanin!"
What came out was a boy in deep blue swimming trunks, with his swim cap designed like frog eyes and a snorkel in hands, like holding a club or sword. He got into a battle stance fitting for a martial artist. His childlike appearance was not for long, of course. Molly pressed his BeastCube at her chest, and soon he aged up. And this time, Molly shrank considerable. She got from voluptous woman down to a teenager.
You smiled at that. "Awww. You are still pretty, if it's any consolation."
She smirked back, binding her black hair into a single pigtail. "Careful now. This Beastie normally doesn´t come out against opponents with just one Crest. But everyone else would not be fun for you, so ..."
Meanwhile, in front of Belle stood a boy no more, but a teenager. His trunks had transformed into a full-body suit, and you saw some mean looking knifes and other short weapons on his belt. His hands and feet were bare, fingers and toes seemed definitely longer than they should have been. There was webbing in between, too.
Of course, his suit was skin tight. Of course, he was built like a model advertising high end underwear. You thought about calling Belle back and summoning Josh, just to see them both side by side, for ... studies.