1. Cap
2. Elektra
3. Sabretooth
4. Mr Freeze
5. Poison Ivy
6. Cyclops & Emma Frost
7. Fantastic Four on foot patrol no J.S. supernova action.
8. Brother Voodoo, FP Blade & Black Panther
9. Batman in a bat-jet
10. Jack Hawksmoor
11. Dr Manhattan
I do not think there is anything in Walking Deadverse that could stop any of them, though I stopped reading awhile back so I don't know what the 'Atlanta City gauntlet' is.
Oh I get it, I only read a few issues, but I know that they respond to sound, so that would draw every zombie within earshot, and if others saw them, then they would follow.
Oh, just full of zombies? Then they're all fine. They can all outfight the ones in their way and make it to places the zombies can't reach.
Freeze is I think totally zombie-proof.
The one in the most dangerous is Ivy (though her planet metabolism probably makes her immune to the virus), but once she gets to some plants she should be fine too.