Bans for Ascension?
Please also write why you ban them
I ban 
and 
Teemo because once he gets shrooms he can kill people or take them to half health with them and ther is nothing you can do about it other than have a banshee or qss for auto attack champions looking to fight him.
Rammus because hes anti ad and can kill mages too. He also gets around the map fast with his q
Poppy because she beats most champs in 1v1's when contesting a point and is super hard to kill, she one of the worst champs to be ascended on the enemy team along with singed/alistar/Amumu
: Very, very annoying in these narrow corridors. Almost unkillable as ascended.
because he's more troublesome than Teemo, always backcapping points when the team is busy, easy escapes and assasinations and so on.
and 
because tanks benefit from the ascendant buff better if they don't build CDR tank items. (All it takes is a warmog's and the HP debuff barely matters.)