Tezzeret is a planeswalker who wields blue magic. His specialty is artifice: spells that forge artifacts, manipulate artifacts, and even bring artifacts to life.
Tezzeret was a talented artificer from the Alara shard of Esper. Like all Esperites, he has part of his body "enhanced" by the magical alloy etherium, part of an overarching planar venture to create perfection of both body and mind.
Tezzeret became an initiate of a mage sect called the Seekers of Carmot in order to gain access to the Codex Etherium, a sacred tome the sect claims to have in its possession. When he intruded into the sanctum of the Seekers, he uncovered truths that others didn't want him to find, and he found himself trapped in a conspiracy much larger than himself.