You do know that 1% of HP is a half a hit point, yes? You start the game with 50 HP unless you take Ironman for your first trait. And we already have an Angel Arm effect on the Trigun, and that's already an anime reference. Angel Arm cuts 5 HP from your total, so that's a 10% drop if you're invuln, first use, and not used Ironman.
And before we call Raging Heart girly, let me remind you that Yuuno Scrya, the ultimate Defensive Mage within MSLN, was its previous owner. I don't think he cared about it, though.
EDIT: Didn't see that it had been edited; what I meant by drop the damage by a face was to drop the second number, not the first.