I know exactly what this game needs

Bravojeen

synergy partner team by Tags like 5 members of the avengers or black order this strike will give a big boost to ability or attack bonus that's will increase the value of older characters who have no place in this game at the moment

Lemon_Man44

But there are newer and better version of the avengers. I suppose you could make it so you had to have 5/6 of the og avengers