Epsilon

The Magnetic Phuse! They can switch forms of gravity, so can in fact walk on walls and ceilings if they want to; they can also lessen/strengthen the power of gravity, allowing items to float, or be pinned to any surface. They more or less keep intact the planet as well as the most basic law of gravity, so if they were to die, well--

It'd be quite the grave situation (yes hi Gret this one's for you--)