If both targets are illegal, the ability doesn't resolve.
Phyrexian Unlife Compleatly awful Few cards portray the fear-factor of the Phyrexians like Phyrexian Unlife
Ray of Command ( Ice Age/Alliances & Mirage/Visions/Weatherlight ) The quintessential combat trick in all of limited Magic , Ray of Command was a first pick card virtually on the caliber with red X-spells back when they were common
The immediate frenzy had a chance to die down, and keep in mind that this was one of the rarest cards in packs, needing approximately 400 Collector Boosters to come up with one copy
Animal Boneyard Bubbling Cauldron Diamond Valley Disciple of Griselbrand Doomgape Gibbering Barricade Gutless Ghoul High Market Life Chisel Miren, the Moaning Well Ob Nixilis of the Black Oath Severed Strands Starved Rusalka Temple of Aclazotz Titan Hunter Vampiric Rites Witch's Cauldron Worthy Cause
Flying, first strike Whenever this creature mutates, you may cast target noncreature card with mana value 3 or less from your graveyard without paying its mana cost