This is more complex then most think.
Omega shouldn't be dismissed so easily. Aside from his death spores, those tendrils can drain lifeforce from an individual. Additionally, his carbonadium tendril and armor can regenerate them if damaged, from what I can remember. Red's also gotten into a one on one fight with Colossus, taking Colossus' best shots.
Venom, I don't think would have a problem with the death spores but that life drain might do him in. There's no evidence Venom's healing factor is superior to Logan's, and Omega has step on Logan many times.
Vengence can regenerate like Ghost Rider right? But how would he do if his lifeforce were being drained?