change the 'decalmax' value in the characters FPE to a high number like 12, that will spawn like 12 blood splats for every shot of damage he recieves.
Then in the decals folder find the blood splat decal, copy it and create a new bloodsplat decal (with a new name)
Change the FPE of this decal so that it includes the line
scale=200
then in the characters FPE change his
decal1=blood
to
decal1=YOURNEWBLOODDECAL
This should do the trick.
"It's often better to keep your mouth shut and let people think you're an idiot, than to open it and confirm their suspisions" - Noel Coward