Sion's E
Is extremely cost efficient. 2.5 second 40% slow with 105 base damage for 25 mana is simply too much. That is IF he hits you with a minion, however if he does not hit you with a minion and just your champion he deals 70 damage with the same effects but ALSO reduces your armor by a 20%! I know he needs a way to land his charged Q but this seems overloaded or way to cost efficient to me.