I don't know who to upgrade!!!

Piikachu021

So currently i have 4 5* and they are: Duped Winter Soldier, unduped quake, unduped task master and unduped ultron, but i don't know who to upgrade, i want to upgrade winter soldier but his PI is so low, i heard quake and taskmaster are good. So if you guys got any advice on who is better please help me.

belli300

Quake

Piikachu021

I though so too, thanks