[@Jarrid]

Even as the defenders opened up on the World Eaters that were charging their positions, two of the more faint hearted of their number near the back had taken fright at the Marines that were coming towards them. Turning to flee like cowards, they instead dropped to the ground as they clutched at their heads while screaming in purest agony. Their muscles forcefully shifted, their bones snapped and knitted themselves back together in new, stronger shapes as their skin was rent open to revel fissures an unnaturally red, unholy glowing substance that hurt the mind just to gaze at. 

The same unholy glow seemed to consume both of their eyes and at back of their throats as they wordlessly screamed in agony before surging upwards to their feet like a puppet having their strings pulled... before turning around and letting out a roar that sounded like a mixture of the deepest of pains and the most all consuming of rages as both of them charged towards the World Eaters at speeds normal humans shouldn't have been able to ran at, one of them swiping at the head of one of his former, unchanged comrades as they pasted and taking his head clean off with a demonic looking claw!