Trent was ready to receive a beating of his life and clean up after his master was done with his rampage. He'd been with the Blakeson family for all his life, he served his father before him.
During his youthful years, Gilbert had a very weak will according his father anyway. He was full of life and innocence, his mother was able to shield him from his father's cruelty until she died unexpectedly.
That's when everything changed for him, his father made it a point to beat that weakness out of him and it worked rather well. Trent watched as he was robbed of his loving and carefree nature, turning into an ever angry monster that was always hungry for more.
Of course he was just help, there was nothing he could've done to stop the change. That's why he never left, that's why he endured everything thrown at him because he felt guilty. Maybe Gilbert didn't remember those days, but he did.