Looks like I'm late to the party but heres what I've used in the past...There are two basic ways to build "Invulnrability" in champs, Damage reduction and Absorbtion. They are mirror images of each other, Damage reduction is pretty much "invulnrability" as it just plain ignores damage, and as an additional bonus it's efficiency increases with the power of incoming attacks (ie: it ignores more and more damage as the attack becomes more outrageous) its downfall is lot o' small attacks so you shrug off Omega-beams, but crumple from 10 agents with auto-fire. Absorb works just the opposite, lots of small attacks make you feel Better, but you can choke on too much energy at once,both are perfectly playable...if you Need gross use both but I for one would never go for it. Heres a "basic" version of a gross "Unkillable joe" Damage reduction 3/4 PDr and EDr...120 points,10D6 absorbion PD into Stun and BOD (+1/2) same for ED...150 points LS all chem and Bio...20points Total cost 290 points,so you have 60 points to build a cometant normal who can shrug off a 20D6 ARx2 killing attack. Good enough for me...