If Mega Damage is a half-reference to Rifts (and other old pen and paper Palladium RPGs) then that's awesome. But Mega Damage isn't nearly the end of things... just imagine:
"This tank has 50Mega HP..."
"He's past normal Dodge cap (dodging 100% of normal attacks), but he's only avoiding 12% of the Mega hits he takes."
"Lol, Stam-stacking nub."
"My heals are critting for 17Mega health, and I can't keep him up!"