Demetrian Titus,Ultramarines

First Strike, Menace, Vigilante.

For the Emperor—Whenever Demetrian Titus attacks, another target creature gets +1/+1 and has Menace until end of turn.

Son of Guilliman—At the beginning of your upkeep, you gain life equal to number of Astartes creatures you control.

-"My Pledge Is Eternal Service"