Ok I got a good one here: Deadpool vs Alex Mercer! Both have extreme regenerative abilities, both are immortal. And before u say it, Mercer is immortal, the health bar was a gameplay mechanic for prototype. The truth is Mercer can only be killed by one of two means: consumption by another Blacklight being, like what Heller did at the end of Prototype 2, or complete annihilation, as in drop a nuke on him. Honestly this isn't even a real death battle cause neither one has the means to kill the other. I'd give the fight to Mercer to be honest. I got another one planned too: Tony Stark vs Samus Aran! Look for it soon!!