The sorcerer survived. Miraculously so it seemed. That was a complication to be addressed later, but Ashtor ran past him and the others to the boarding ramp of the thunderhawk. "Agreed cousin of Fulgrim! Let us leave." Let the sorcerer burn or seek his revenge later. But he was secure in the short term with his knowledge of flight and the protection of the sons of Fulgrim who needed him alive to make the Thunderhawk do just that. Brushing through the ranks of the pink warriors in his rush to reach the cockpit of the craft.
He dared not let lose more plasma towards the internal confines of the transport less he irreparably damage something important. For that reason he could not risk more bolter rounds to be fired either. So the first Black Legionnaire he could reach found the jagged bayonet of a stolen and corrupted plasma gun jammed towards his chest. "Get me to the cockpit!" he roared as he descended into a duel with the black Legionnaire. A duel he did not plan to fight fairly. Following his momentum of the baynot charge and crashing shoulderlong into the dark warrior. They both slammed into the inner hull of the Thunderhawk with a reverberating thud, Ashtor felt a combat blade bite into the soft armour of his side and focused that lance of pain and the rage it brought forth to fuel his limbs. Grabbing the hand that held the blade his other smashed the body of the plasma gun into his opponents head. Probably doing the finicky coils and complex internals of the weapon no favours. But he continued to pin the warrior against the hull, dropping the plasma gun and scrambling for his own combat knife. It was hard to fumble for a blade while one was imbedded in your own body. Even for an astartes every twist and turn sent waves of pain through him.
Despite the difficulty with wrestling a rival chaos marine one handed Ashtor managed to slip his own blade into the soft armour of his foe. Now it was little more than a free for all as he lost the grip of the legionnaire's knife and they were both locking arms and rolling against the thunderhawk. This exchange went on for what felt like an intollerable amount of time before Ashtor ended it by bashing his helmet into his opponents and driving his blade upward into the neck and brain. The blood that oozed out of the legionnaire was as black as his armour and just as tainted. He could hear it dissolving the combat blade like an acid. He left it lodged in black armoured corpse and ripped the blade stuck in his side out to keep for himself.
'Let the Emperor's children finish the rest' he thought to himself, limping down the thunderhawk to the cockpit. His plasma gun recovered and dangling from his left hand grip while his right held his newest possession, a combat knife bathed in his own unnaturally dark lifeblood. His superhuman immune and recovery systems couldn't fix the damage done to him so quickly.
There was one more legionnaire in the cockpit. Obviously waiting for the fighting to be over so he could lift-off with his brothers and escape this failed invasion. He died far quicker than his brother in the back. Ashtor left him to rot on the floor and took his place in the pilots seat. Sucking his sharpened teeth because of the pain flaring in his side. He didn't really care who was or was not onboard at this point. The warchant of the mechanicus legions was too loud to ignore any longer. Their guns were too close for comfort. "I'm closing the ramp!" It wasn't so much a warning that gave the stragglers notice to rush inside the safety of the adamantium hull as it was a statement that said stragglers were now on their own and likely faced their last few minutes of life.
True to his word the powerful ramp sealed whatever passengers it had inside. It was time to get the fuck off this world.