Zegaana

She was raised on a Native American Reserve but due to industrialization it's in massive decline. When she's about 11-12 Yggdrasil barges in and starts making plans to build a hospital or drug processing facility uncomfortably close to the reserve and Zegaana does not like that (pretty much everyone in the town doesn't but her in particular). The village elder notices she's extra unhappy about the situation and gives her an ancient heirloom bey that could potentially do something about the situation. She's told if she is worthy of the Thunderbird's Blessing, the bey's true power will be unlocked and the elder tells her to climb this particular mountain and let the bey do the rest more or less. 

She's like "Aight" and proceeds to climb this mountain on her own and eventually she makes it to the summit during a thunderstorm in which she gets struck by lightning but at least the bey got a glowup. She comes back and ends up destroying the construction site with her new bey. After everything is resolved, she decides to go on a training journey and starts with Japan since one of her parents originally came from there.

When she gets to Japan, she eventually meets the Horned Serpent and Underwater Panther Bladers who become her teammates and they start making a name for themselves (in the Amateur League most likely) and it apparently attracts the attention of Fujiwara Burn (if he's old enough). They are invited to be sponsored by them but Zegaana refuses almost immediately and ends up leaving the team.