the decay of angels took a liking to you because you’re of your ability as you were an omnipotent ability user so to get more information about you they found an ability user to turn Nikolai into a cat (against his will) but Nikolai actually found it entertaining and decided to stay and play along.

Later on through the mission though he found out he could turn from cat to human and back to cat while you were out.

today you came home from work and saw him in his human form