"It's not fair that I have to rush zhonyas" - Mid Lane Mages
Well thats to bad :D, you can't have everything. Riot's not gonna give you mana regen , invulnerability, and everything else! Be good at the game and learn to manage your resources.
Riot is giving you a item that pretty much 100% nulls zed from ever killing you, and your complaining? "But my mana regen", You shouldn't mindlessly spam your skills then. Manage your mana. "But I only have one choice against him" And that one choice is freaking amazing but you complain because you also don't have mana regen.
Your lucky that their is such an item that counters him so hard. Zed's an assassin you shouldn't be able to beat him in the first place.
Zed is the best duelist in the game, be grateful such an item exists.
as long as it keeps the enemy assassin from getting fed.