Fenris was a rather vengeful person as pointed out several..upon several.. times. At some points it got in the way of your relationship with him where there were several times he lashed out on you.

The last of which being after the slavers returned to find him and bring him back to his old masters apprentice, Hadrianna. He lashed out on you after she was slain by his hand.

Just a few nights later he sat in the entryway of your estate, sitting on one of the benches. He came to apologize for lashing out on you, dawned in a new crest sitting on his belt , Your family crest, each indent painted red in the silver.