Still hit really hard? Are you joking? Pick disintegrate for eg. A lv 20 barbarian with 20 con with average rolls and +5 con mod would have 19 * ( 7 + 5) + 12 + 5 hp or 245 HP. The average damage of disintegrate is 75 damage(10d6 + 40), which means that a barbarian on 5e can survive failing 3 saves and being disintegrated 3 times.
Couldn't think of a more extreme example? :P
You get Disintegrate at level 11. It can one shot many 11th level characters who have taken a small amount of damage from something else and will reliably one shot characters a couple levels lower. Sounds powerful but still balanced to me, assuming you can't spam long rests at will and do it in every fight.
A lvl 20 Wizard can cast Imprisonment and permanently shrink a level 20 Barbarian inside a gemstone and make a pretty amulet out of it. Not powerful enough?
