Batrangs do 3% chip.
Superman does 5.5% with zap, 2% lasers.
NW does 2% with spark, 1.6% with staff.
DS post nerf does 1.2%.
Cyborg does 2%.
Sinestro 1.25%
Green Arrow gets .1% normal arrows, .7% with fire and electric arrows. Frozen arrows do nothing.
The reason for this, obviously, is...