Because he's harnessed the magic power of Tampax? No, because he's lured the FF into his hall of mirrors, surrounded himself with his impenetrable Block of Glass, and he's about to hurl his Disappearing Spell at the FF. Note to future Dr. Weirds: if you do indeed have a Disappearing Spell, use it right away. Just cut to the chase. Do not lure your prey into a hall of mirrors, and do not announce that you are about to hurl the Disappearing Spell at them. Any fool can see what happens: they duck, the spell hits a mirror, bounces back and disappears you.

Take my word - you get the FF together in one room, just flood it with sarin. You'll miss that all-important taunting interplay, but you won't end up a one-shot villain. Study the classics: it's taunting that does 'em in, every time.