- Adolph Hitler has the Mind Gem
- Joseph Stalin has the Space Gem
- Zedong Mao has the Power Gem
- Kim Jung Il has the Time Gem
- Saddam Hussein has the Reality Gem
- Osama Bin Laden has the Soul Gem
Battle in the Cosmos.
Explain PIS if deciding to use it.
WOW that title!
On topic: While the Sinister Six have the gems, the Cosmic team has the experience in how to use them. Not to mention that each of the gentlemen you listed just want power. They'll be cutting each other to pieces to get the other Gems before the opposing team tries ANYTHING. Thanos and Mephisto are master manipulators, Onslaught has all the telepathic power of Charles Xavier, amped by the Cosmic Cube, Franklin Richards is a high class reality warper on par with, if not exceeding Celestials all alone, much less empowered as Captain Universe, and Abraxas is to universes what Cookie Monster is to cookies.
The Sinister Six has NO CHANCE IN HELL.
Mephisto makes sure of that part.