Azmuth (Aliens Unleashed)

Azmuth is the creator of the Omnitrix, Ultimatrix, and Infinity Matrix, granted a majority of work on the latter was done by Azmuth's first partner, The Master. He is responsible for The Master's initial imprisonment, hence The Master's sudden urge to kill Azmuth during his first encounter with Ben Tennyson, in which Azmuth is present.

The Master succeeds in killing Azmuth, his last real threat in his opinion (at least until he becomes more involved with Ben, Gwen, and Kevin), but the elderly Galvan's legacy lives on within Ben, as seen by the young hero's wiser decisions regarding the Infinity Matrix now that he has been left on his own to save the universe while solving its mysteries and learning to use it.