Osmosian

Osmosians are an aliens that look like humans, The name 'Osmosian' is a play on the word "osmosis", the name of the physical process by which a solvent, (i.e. water) diffuses from an area of a high concentration through a semi-permeable membrane into an area of low concentration.

Osmosians are able to absorb, hold, redirect and discharge various types energy through their bodies mostly electricity and lightning. It is apparently ill-advisable for them to absorb raw energy, such as electricity, for Osmosians that have yet to fully mature as it can effect their physical and mental state (which might explain Kevin's lacked control of transforming into Ben's original ten aliens and then mutation whereas his future counterpart could freely control his absorbed powers and may also explain his aggressive sociopathic behavior in the original series). Osmosians and half-Osmosian are also able to absorb the mass and properties of physical materials and grow an armor-like outer skin as durable as the material used to make it and by extension proportionately strengthen and increase the Osmosian's strength and durability to even higher levels.

when Osomsians absorb the energy from other life forms, they gain that life form's powers. However, they are only able to use only 1/10 of the original creature's powers and abilities.

Little else is known about Osmosians so far, except that they are outwardly indistinguishable from humans except for the fact that Osmosians live for hundreds of years, and after about one hundred years when an Osmosian is fully mature, they begin to grow antlers (confirmed by Dwayne McDuffie).

Trivia

 * It is also hinted that Osmosians, as a culture, have spiritual beliefs, as before he died, Devin Levin told Max that he'd be watching over him from now on.
 * there is Osmosian DNA in the Ultimatrix.