Crit chance boost (target) self.
Enemies using this as addition to own critical chance, i.e. enemie.crit chance + player.crit chance vulnerability, which returns positive number.
When I say "sofia's perk" actually I mean this is a perk given to player after beating sofia; it's one of the perks you can choose, not one she has for herself.
So, in both cases, the stat in on player, but they have opposite descriptions, but both have positive values. One of them should be negative. So, as you said, if an enemy has a 50% crit chance:
player with none of those perks: 50% chance of taking crit
player with enduring body: 50% + 10% = 60% chance of taking crit
player with touch of ecstasy: 50% + 5% = 55% chance of taking crit
Maybe it isnt flat addition, % values could be multiplied (50% * 10% = 55%), but the point is, one of the skills is wrong, right?
Editing, did the test by changing the values on both perks and testing them on a new game. The perk is indeed wrong, but in touch of ecstasy.
On both cases, a value of -150 makes every opponent attack crit, so it should be -5 on touch of ecstasy stat. Enduring body was correct.