Level 3 for Zelgadiss and Pretty Butterfly. Since both wiki articles are a bit on the sparse side you can feel free to inquire with me about anything not contained therein (especially Zel, who's had weird things happen to him due to the community during a gap in canon and as a result is currently no longer a chimera).

Jak I'm putting at Level 0. I don't know if he actually has any specific psychic resistance or anything, but we can chalk it up to the power of the Precursors and him being something approaching a Chosen One (they didn't have a backup hero, but if they did he's who the backup hero would be for). Given how the Precursors are with each other, I'm not sure they'd play nice with other supreme beings, even if they are a bunch of fuzzy little rats.