i feel like these are common suggestions 1. Allow people to see their teammates gear and level in team up.
a great example for this is Loremaster, where both high and low levels roam. you see a in the team up kiosk, and decide to make your deck speicifally to buff him and his attacks. next thing you know he's only level 40 and have to rely on your teammates to do the attacking (it takes waay too long for me to solo loremaster as a .)
this will make balance a bit better at soloing and they won't be stuck with Spirit blade and trap for 43 levels. balance also won't have too much of a trouble using spirit blast as spirit schools get a boost towards balance.