Rater's Extended Signature
Undying One: Base Class built entirely around being as hard to kill as is balanced, fluff neutral, no-ability-dependant, though a high con score is encouraged... Not much else going for it, admittedly. Meant to be taken from 1-20, but the potential exists for dips and multiclassing and it is made with that in mind.
Super Soldiers: Create Captain America as a PC or NPC ally... Or Nuke as an enemy. Also includes Man-Thing.
Subclassess: Symbiotes for Every Class.