During the [[Great Crusade]], [[Fulgrim]] was invited to meet with [[UlthweUlthwé]] [[Farseer]] [[Eldrad Ulthran]] on Tarsus, where the [[Eldar]] attempted to warn the [[Primarch]] of [[Horus]]' corruption. Upon discovering the [[Blade of the Laer|corrupted blade]] at Fulgrim's side, Eldrad realized that the Primarch was already doomed and ordered his [[Wraithguard]] and [[Wraithlord]] guards to slay the [[Astartes]]. A vicious battle broke out that saw Fulgrim destroy both a Wraithlord and [[Avatar]] of [[Khaine]]. In the aftermath of the battle, an enraged Fulgrim had the planet destroyed by [[Virus Bomb]]s.{{Fn|1}}