without pis warlock should win. If got serious he could probably turn into a being similar to his dad or that giant technarcy Siredam that fought Nova Prime.
IIRC Magneto at that point was explaining to Warlock that he should never try and drain the life force out of any sentinent being. Herc blindsides him from above w/ his mace. (Warlock was a jet at that point carrying Magneto) Later in the issue an injured Warlock was draining the life force out of the Avengers until Mags was forced to attack Warlock so he wouldn't kill them.
If Nova prime can get put down by the virus I don't see why Herc wouldn't. Is there an on panel showing of Herc actually resisting the virus?