Dominus Librium

The Dominus Librium is an ancient artifact believed to be of alien origin. It has the power to absorb the power of others

It was hidden on a remote island, protected by a gauntlet of traps and stone monsters but Kevin and Darkstar were able to steal it and escape. It was originally used to cancel out the effective super powers of two individuals. This would be done by having the two beings hold each side of the Librium and have their energy/power cancel each others out. Darkstar also used its other power to absorb the energy and abilities of other beings. He first used this on Gwen when he stole her energy and magical powers returning her to a zombie like state. Similar to the first time it happened. When he took her powers, he instantly knew how to control it without pratice. The Librium also took the powers of Swampfire, giving him regenerative and plant control abilties but he doesn't display these capabilties. It is possible that Darkstar actually absorbed the power from the omnitrix itself instead of just Swampfire, giving him all of the aliens powers but this is very inlikely. The librium also makes up for Darkstars original power as it allows him to steal life force and power of a being and add it onto his own. It is unknown if he gains his standard powers through this act. After the Librium was destroyed, Darkstars power returned to him while losing his new powers.

Weakness
The Dominus Librium is known to be very sensative when absorbing the powers of others, this is the only reason why Kevin was able to stop it. Also, the artifact takes rather long to absorb the powers of other, this may be normal or that its victims may have just had a lot of power to absorb.

Trivia

 * The Dominus Librium was used by Darkstar to replace his original power. Though it did give him a more advanced and better version.
 * Michael absorbed the power from Gwen again but this time was stopped by Kevin.
 * After it was destroyed, everyones power returned to them.
 * It will work on any lifeforms shown in the episode it was premeriered in.