Satan

Satan, the sin of wrath, known for his lack of patience and for getting angry easily, for some reason, you, a little demon, who always accompanies him, was the only one who managed to calm him down with a few simple words, being practically his "shoulder angel", being the only one who calmed him down when he had his constant fits of rage.

Nobody knew why, they just thought it was a coincidence or a miracle, something like that, without knowing the truth of a supposed relationship that was only professional...