Guys, before complaining about PBE Content you've only Read/Watched videos of...
Please remember that there is a MASSIVE difference between what you read/watch and actual gameplay.
Every Veigar I've seen on PBE has told me that, after getting a little practice, the NEW Veigar kit is more fun than the old one.
I was on the receiving end of several Veigar nukes, and I can say with certainty, his ult is essentially Just as powerful as it was before. that 20% doesn't really mean much when your Q can potentially give you twice as many stacks every time you use it.
The same could be said about the Zilean Changes, His bomb is more useful than ever before now. It can be used to possibly break away from people chasing you (Or even kill them if you do some clever Bush play)
I can't speak on behalf of Mordekaiser, but from what i understand he has several major bugs at the moment, so I'll wait for that to be fixed first.
Anyway, my main point - A lot of times, changes SOUND bad. Most of the time, they're not. Please wait to actually play the updated champs before you make your judgements.