Buff Ekko's base mana per level.
I know people will downvote me if I say that his early game sucks, which it does, vs some matchups(Irelia), so would it be so much to ask for a late game buff? You won't be buffing his damage any more. You see, Ekko usually only gets 1 mana item, which is Lich Bane. This item only gives 250 mana. Sometimes, Ekko gets Mejai's soul stealer, which gives 200 mana. It feels so horrible to run out of mana during a teamfight, which happens pretty often(about 1/3rd of all teamfights). He is not meta, he is not OP, this buff will not make him meta or OP, but it will help him out a lot.