When Eternal Scourge dies as a Vampire due to Xenograft, Timothar triggers, causing you to pay ({1} magic symbol) and exile Eternal Scourge to create a 1/1 Bat creature token.
Activate Ashnod's Altar by sacrificing the Bat, adding ({C} magic symbol) ({C} magic symbol) .
Cast Eternal Scourge from exile by paying ({3} magic symbol) .