Spores and Life drain off. Omega-Red vs Spider-man.

Also depends on armor. The black and gold held up to terrax's axe

It did? I remember Illuminati fighting Terrax, but not that specific scene.

Anyway, it was a Terrax from alternate reality, IIRC. Means the planet-busting feat is not usable for him.

I dont think Spidey is strong Enough to seriously hurt Red. Hed need a weapon that would be able to penetrate him and his armor, hitting a major organ or something.
I dont think the armor that Stark was mentally controlling was some regular piece of junk. The armor should still be highly durable even without shielding. If caught in the tendrils, its not looking good for Spidey at all. Thats more likely to happen than him being seriously hurt by SM. Imo. 🙂

Modular armor is one of my favorites. Of course it wasn't a piece of junk.

Hell, that armor is a symbol of the excellent season 2 of IM TAS from the nineties.