Yes and shooting them in the head doesn't always work. You have to aim for a SPECIFIC part somewhere on the head (forgot where). Captain America zombie got most of his head sawed off and he was just fine.
As to the thread : IM. He can chef up some engine to recharge his armor if he needed too.
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..even the outer hells are indifferent matters for they bow only to potent and archaic Nodens.
Yup, people don't understand IM aka Tony Stark is a genius inventor. First thing he'd do upon entering a strange universe that he's trapped in would be create some way to power his armor. Since he's an Earthling and has intimate knowledge of our tech and cities, he'd have an easier time than say Vader.
Dark Vader aka Annakin is also a genius inventor. The difference is, our world and technology are alien to Vader. He'd have a harder time coming up with something to keep his armor powered. Remember he has no arms and legs, without the armor to grant him mobility he's phucked.
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..even the outer hells are indifferent matters for they bow only to potent and archaic Nodens.
In any case yeah he's got lots of options for recharging once he's settled in. The big advantage Iron Man has over the others is flight - he can simply leave the vicinity at any time if he's bothered by zombie (or human) cretins. He has a much easier time scouring the countryside over large distances for food, water, and tech. There would be tons of stuff left around. He could pretty easily get into supply depots or high tech installations from the air without having to fight through all the time or waste time walking/driving long distances. He just needs to find a suitable building or natural location (or better, several locations for backup) which is completely inaccessible to the zombies from the ground - skyscrapers with blocked floors, mountain tops etc. Maybe set up some safe houses he can get to even if something happens to the armor. Then with his skills he can amass supplies, tech, and luxuries, build solar (other whatever) reactors, water purification, hydroponics, weapons, and so on. If possible leave spare suits/weapons cached around just in case. He can easily move even large stuff around for fortification or supplies (although Vader and Cable can TK stuff I guess). With the right stuff in place he should be able to maintain himself well for quite a while.
I can just imagine Lord Vader checking out abandoned cars for good ones, siphoning petrol, hot wiring, taking off down the highway in an old pickup with zombies on his tail...
Wolverine, simple survival would be significantly less of a headache, because let's be real, the zombies aren't going to be a problem for any of the choices in OP.
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Besieged by countless foes, his eyes they are aglow, longing for the fight. He stands upon a mound, doesn't aim the throw, just lets the hammer fly!