A broken champion is a champion that is unfair and/or breaks the rules of the game in a bad way (like zoe W but on a higher caliber)
Saying he is broken is stupid, atleast say he is OP. And even then, that's a different story. He does not break the game, especially with R which Kayn has a bootleg of said ultimate.
youre right he isnt broken he does his job.... just too well ...........
You are right partly, but I think the reason why people are not happy with Zed being buffed or just Zed in general is because of his R not being interactive (Point to Click ability) and how you can't play against it besides 
or unless you are a mage who can just 
. If you are an AD champion however you are forced to buy 
which won't be of any use considering how fast and weel Zed's damage scales and how low of a cooldown his R is now after the buffs.
Honestly Riot needs to consider completely changing his ultimate ability or change it slightly how it works, because currently:
No , Zed IS broken , he can kill most of mages whenever he has his ult ready , if he suffers against bot lane meta , if he suffers against heals and shields , then that means mages would suffer more from that , even if Melee, Zed can run with his Shadows , while if a Mage is caught , that mage has no Run Yasuo , Zed , Lee Sin , those player base who always try to play a high skill gap champion , but they can't admit the more difficult the champions is , the more you can do with the champion.
Wait this post is being downvoted, for saying that "Zed isn't strong". But a different post where it states that "Zed is broken" is also downvoted.
:Thinking:
too many invincible frames, Q shouldn't go through minions full dmg, electrocute breaks and procs off nothing, all in lvl 2 while further back than 90% champs in lane, builds AD and gets auto scaling plus op ratios and early game. also no costs on any spells
