Dianna vs Zed

Diana is actually decently good-ish and can be played in top, mid, and jungle (although top is rare). Zed is garbage and is pretty much strictly limited to mid.

Shoot for the moon, eh?

Less popular, prettier, gives your jungler and top more freedom to choose what they want (Because if you have zed mid and an ADC bot, someone else will have to go AP top or jg).

But in the end, the choice is yours. I picked Diana first because I really liked that double dash ultimate thing.

As much as I hate saying it. Diana is better at the moment. Although depending on the assassin update this could change rather quickly.

She is more versatile then Zed. However, the current meta is a bit rough for her but, she has it better then Zed. Mid is where she is strongest at she scales very hard but, zed is far safer and his sustain is better. Jungle is mediocre at best, weak early game, poor ganks until 6 and she requires expensive items. Top she is currently pretty weak, she loses most match ups.

Obviously I prefer Diana over Zed. Both have their strengths but, ultimately it's up to you.

Diana's definitely better right now.

Overall it's more a question of preference though, as always. Zed's much more of an in and out assassin, while Diana tends to play more like a bruiser. Her damage output is a lot higher and she's kind of tanky, but she doesn't have ways to leave a fight.

Also she gets to build protobelt which is a completely disgusting item.

Diana. More versatile, stronger role in team fights and much easier to play. Her burst isn't gated by a huge ultimate CD nor is she hard countered by exhaust, zhonyas, etc.

Also zed gets banned because mid laners want to rush mana regen and clear waves without strategy. You'll play much more Diana than zed.

Diana if you want to win more.

Zed if you want to feel cool about yourself.

Diana if you want a mechanically simple assassin/diver (although probably more difficult decision making wise, as no easy escape).

Zed if you want someone mechanically super tough.