Ashtor needed to make a decision. The fight for the thunderhawk became more and more complicated as the scions of Angron and Magnus made their appearances. He didn't care about them but they were obstacles to overcome. The Black legionnaires fate was all but sealed. One didn't have to be a seer to fortell that all of them would be dead within minutes. But there were enough of the Slaaneshi marines that they could still control this fight. He could manipulate that. Being born a slave and therefor a half breed in the eyes of his brethren, Asthor always had to play politics and power games to survive. Deciding which squadmate to support as the new squad leader, which acolyte to swear allegience to during a power vacuum in his warhost. All of those decisions were carefully thought out and weighed for which was the best option not only to keep him alive today, but to help elevate him tomorrow. It was the reason he sided with Amon the Defiler and now stood as an aspiring champion of his own right. And it was the reason his minded calculated the greatest chance of survival lay with convincing the numerically superior Emperor's children that he was a trustworthy, or at least worthy temporary ally. As the rumble of Skitarii war engines grew ever louder he had to act quickly. 

He saw his chance while the sorcerer seemed engaged with the Khornite. Plasma shot was rare and valuable but he could spare a few shots if it meant putting down a sorcerer. 

“Cousins of Fulgrim!” 

Sprinting forward from his hidden position. Loosing a glob of super-heated blue gloop through the air aimed directly for the distracted sorcerer's chest. 

“Take the ship, I can fly us off this world! Kill the son of Magnus!” 

Drawing the pistol from his hip he followed up the plasma bolt with a few bolter rounds aimed at whatever Black legionnaires were still standing, And at the Khornite's back. He could only hope this display would earn him the trust he needed to convince them. 

“The metal legions are upon us, we must leave! NOW!!!”