Despite their best efforts in a hard-fought battle, Nadia's group failed to perfect one aspect of their almost flawless ambush, and that was compartmentalizing it.
Boom
The explosion that occurred caught Charles by surprise, forcing him to push back to protect himself from the terrifying force.
The source of it all was Frederick, who, in a bid to ensure the safety of his brethren, willingly gave up his humanity, quoting a most profound scripture in his final moments.
"My God, into your hands I commit my spirit."
His armor dissolved, same with his flesh, leaving behind a body of light that gave off faint traces of radiation.
Its radiance caused degradation at a cellular level, ensuring that no one was safe.
As Nadia's group sought for cover, The Keepers took the opportunity to flee, steeling their nerves as they knew that they would never set eyes on their captain again.