It's just an unfortunate twist of using his greatest past trauma against him at the most (in)opportune time. He honestly could've gotten away without this much damage... were he a stronger person. He knows his strengths, he knows his weaknesses, and unfortunately the human brain could only handle so much no matter how tough you know you are.

With no other words, he flattens himself to the floor in a flurry of smoke to try and track down the noise. Where it's coming from. A brief recon tells him they're coming down two of the connecting tunnels, assuming they'd followed the noise they made after lifting the panels. Like the slow and clunky march of the Bastions, they come jogging down the corridor, machine guns at the ready.

He presses up against a wall, staying out of sight for the moment. Squeezing his eyes shut, he tries to shake out the smell of dirt and blood, debris flying through the air in the darkness of a long-forgotten field and he's twenty-five again. Then he's thirty-five.

A shot rings out and his eyes snap open.

"—Grngh!"

Pain blooms in his arm as a bright red bullet, heated from the fires of the monster's gun cuts across his triceps. It's the trigger he needs as his brain suddenly gets ripped back into the present and he's blasting the stun ammo at the front line before going in with his bare hands. He hates that he has no real ammo, it's really grinding his gears.