Okay, so this might be the issue.
So the even Risky Assassin out, make him invulnerable against damage over time. Wouldn't make sense anyway, he has only 1 HP.
Another think I would like but is probably unlikely, give him a base dodge chance (like the perk) of 5%, so he has at least a chance to avoid damage. Or maybe soem sort of time dilation. Not as high as The One but maybe the same as the cryogenic module, so you have an easier time to dodge bullets.
So, DID you manage to beat the game with this perk?