Graham McNeill
The Heraclitus Effect

Desperate for revenge against the Ultramarines who humiliated him, Iron Warriors Warsmith Honsou hatches an audacious plan to destroy a planet.
Warhammer 40k
short

Also in:
Eye of Terror
25 For 25
Honour And Vengeance: Uriel Ventris Vs Honsou
Iron Warriors: the Omnibus
Planetkill