In Magic player lore, Mark Rosewater is infamous for a few of his odd predilections. The R&D bigwig hates bananas, has a pathological fear of buses (thanks to an old joke about Mana Drain), loves Squirrels, doubling, and the idea of a third Un-set... Oh, and any planeswalker he expresses affection for is doomed to die. It's happened with Elspeth, but the more famous, and first, instance of this was with Venser.
The temporal architect of Time Spiral fame found himself hunting for Karn on Mirrodin in order to shake the elder planeswalker to his senses, but as Phyrexia closed in and finished their takeover, Venser had to give up his life to free Karn from his corruption, teleporting his own heart into the Silver Golem's body and thus reigniting his spark.
Rosewater made reference to an often-held postulation about Venser on his Tumblr blog recently.
When actualinternetrapper asked, "Who is your favorite dead planeswalker? You can't make things any worse for them, right?" Rosewater said:
Venser. If his corpse gets stolen…
Many players believe that Venser's body was taken by one Phyrexian faction or another and used to create a powerful servant, much like the fate of Ertai during the Phyrexian invasion of Dominaria. Since Venser gave up his spark to help Karn and the Glistening Oil can't coexist with a spark, even if Venser is revived he won't be a Phyrexian planeswalker. However, he could still easily be a threatening legendary creature - as darththulhu said in the comments, "CONFIRMED: Compleated Venser, masthead/captain of a portal-ship."