So I have enough ip to get Katarina, so do you suggest buying her now, or saving for Zed. So this is essentially like a "who is the better champion." Also, can you provide tips and tricks for either champion if you know how to play them.
Thank you for the help.
or 
This question is impossible to answer. One isn't better than the other. They both have different strengths and weaknesses that depend on the team you're playing on, and the team you're playing against.
Katarina is arguably more fun
Kat is blatantly OP but is banned more. Zed takes time to learn
I think Zed is better at securing the kills and getting away, but Katarina has much higher kill potential overall.
Zed is better at reliably killing one target, while Katarina is better at doing less reliable damage to multiple targets if that answers your question.
kat got me to plat 3 and the update only made her better to kite ppl with
As I look on your profile - and I believe it's not a smurf, according to your score every game - I highly recommend neither of these two champions. They might look cool to you but if your average score is 4.9 / 10.4 / 6.9 and you do this terrible with Annie, your game knowledge is so bad that it doesn't let you to focus on controlling your champion, which is very important with both Katarina and Zed. You can, of course, try to play them, but you are going to not even know where you are and it is going to frustrate you beyond your imagination, leaving you with no enjoyment of the game. I recommend watching at least few videos on Youtube (try Tips for Bronze and Gold from PentaMagic channel, it helped me ALOT when I was a beginner) playing champions you don't need to focus on that much, then move to harder ones.
And then I would recommend Zed over Katarina, while she is potentially better at damage dealing (she can slay the whole team while Zed cannot take more than 2 people per teamfight out if not insanely overfed), she does also require way more thinking about her engaging and comboing in the middle of a teamfight.
I prefer kat but I'm biased being a kat Main and all
Zed is a lot easier to play, and he's not the easiest himself, either. So Zed.
Buy zed...... Hes on sale
