My problem with Chansey is that not only is she an amazing wall, but she's also an amazing team supporter with Wish and Aromotherapy. Last generation I would never consider her broken, but with this freaking Eviolite, I may be leaning towards thinking she's broken.
If she was more of a stand-alone wall like Deoxys-D (who isn't broken imo), then I would say she isn't broken. But the fact that she walls half of the metagame and keeps the rest of the team healthy is pushing it a bit for me. Though, I doubt I would vote for her being banned this coming suspect vote (if I get qualified...), mostly because there's some other stuff I want to get rid of first.
On Mew: I'm on the fence with Mew. Most of its sets are easily phazed out or outright beaten by my Snorlax, but there's no telling which set it's running until it's too late. I've been swept 6-0 by a SD version, and then other times a NP version comes along and does nothing except tickle my Steel or Snorlax. I also don't have any problems with the Taunt + WoW one either.
On Kyurem: I really don't think this thing is broken. Too much can beat the sweeper sets, such as TechniTop and various other things. The Staller is a bitch, but if you can get up SR and phaze it out with stuff like Empoleon, then it's easy enough to deal with. It kind of forces you to have a Steel-type on your team, such as Empoleon or Registeel, to absorb its Specs Draco Meteor and stuff, but it's not as broken as Victini.
Now Victini, that's about all I can say that I'm going to absolutely vote for banishment at this point. V-create OHKOing my 252 HP / 252 Def Bold Deoxys-D in the sun? Bitch please.