Louis armor is set in his ID [same with Julian] and you cant change those ID functions without hex editing, so you have to search another way not using ID's.
As you want to make the armour absorb more damage without beeing broken you could probably create a ball which follows Louis through an
itr kind/8 [those always "jump" to a bdy in the same area"] which area is far away from the battlefield. This frame should always repeat itself and should have a state: 3000. Then you have to create a bdy in most frames of louis in the same area, so it will only follow louis.
Next up, you give the
ball a bdy at the position of the character so that it can be hit by balls/punches.
Then give the ball an itr kind 4 [i think? not sure] in the same area as the bdy you made before. in the hit/hitting/rebound frames you can attach a hit_d/hit_a so that the ball takes damage and link with next to the frame following louis again. also make sure the ball has no sound and is invisible.
look
here for more details with the hit_d/a.
I did something similiar with a weapon years ago here
[click] but since I havent D.C'd in ages I cant give you any further details about it :P