Technovore has absorbed all of the armors from Earth 616 that Tony Stark made, and has absorbed all of the Crimson Dynamo, Titanium Man, Iron Monger, and Dr Doom armors from Earth 616.
Galactus is starving.
Battle is to the death.
Remember, Technovore can recreate itself from even the smallest remaining fragment, adapt to attacks (eventually becoming immune to specific ones if it adapts to them enough), and can absorb technology.
All other life on earth is inexplicably in a coma, thus if Galactus can pull it off, he can eat Earth to gain energy.
The Ultimate Nullifier is not allowed to be used by either side.
Edit: Technovore has a week to prepare before Galactus arrives on Earth, and can absorb any tech he manages to find in that time. (I forgot to put this in here when I made the post.)