Unknown to the Ultramarines, their primarch was not an imposing big man, but a little girl. And that her name was not Roboute Guilliman. In fact, the name is actually a nickname given to her by Leman Russ in response to the Codex Astartes, and that the nickname was actually 'Row-Boat Girlyman'.
Xhydralisk said: I had hoped otherwise, as there seems to be no other way to kill the beast.
Turns out Matt Ward is actually what the Tyranids are fleeing from. He's retconned, ruined and defiled everything in their galaxy so there's nothing left but billions upon billions of Ultramarines floating in the vacuum. His thirst can not be quenched as long as there's life left in the universe that's not Ultramarines.