>>60486075On the boys I feel like it'd be Luca, Vox, Hex and Doppio. A lot of the boys have relatively "down to earth" designs with Shu and Fulgur being the biggest exceptions so it's not that complicated to cosplay as them.
The girls started more as fantasy creatures so it's a little harder to pull off, but I imagine Scarle, Aia, Maria, Selen and Elira would be the easiest.