Jarsyl

Jarsyl was a powerful wizard from Dominaria at the outset of the Dark Age. He was the firstborn of Harbin and the great-great-grandfather of Jodah.

Jarsyl somehow discovered a planar portal to the plane of Phyrexia. After entering the portal, he was never seen again, though portions of his diary written while he was in Phyrexia somehow survived. His notes were heavily used in the Conclave of Mages.

In-game references
Quoted or referred to:
 * Gate to Phyrexia