[{quoted}](name=Lord Dusteon,realm=NA,application-id=3ErqAdtq,discussion-id=F6MvNJ46,comment-id=0001,timestamp=2015-10-04T01:52:45.356+0000)
Her Q and W had their scalings nerfed (Q MASSIVELY, W a large amount but not as bad), W lost a huge chunk of base, R lost a large amount of base and some scaling. Her passive was changed into a unfun, uninteractive feeling mess that is useless until X stacks, then massively powerful at X stacks. All of her power got shoved into spamming E on someone instead of actually poisoning them.
So, the main problem is her poisons A) don't do enough to justify maxing or using them outside of E, and B) her poisons feel horrible to use. Her Q is only to refresh E's and for ms, W is only for slows and E's, R is only to stun/slow so you can Q/W and spam E. She doesn't feel or play anything like a DoT/poison mage.
I keep hearing this "poison Mage" crap. Listen up
Originally, Cassiopeia was intended to be a champion who has a playstyle like a adc. Her q and w would poison so that she can use E constantly like an AA. Her Q and w would also help her kite and position. Her r was there to help her stand in mid lane vs champs who can dive her. After all she plays like an adc but has no support.
This is why, if you look at her guides back in s2, everyone said to max E. Mathematically, it did more damage, more consistent, and more effective. Then champs like zed, Yas, vi.etc started getting played and released. She went from being a bully in lane to being bullied. So people changed the guides l, they recomended maxing q because it was safer even if her dmg was a lot lower. So that's when this whole, poison Mage started to arise
Her original design was not to poison and watch them die. She was meant to hit you with e spams and repositioning with q and w, while stopping enemies from diving with her R. This rework did hat again.