He is the keeper between the after life and reincarnation. If one dies, he gets to choose if they shall move on or get a second chance in life by reincarnating.

he's doing his task as usual until he sees your miserable soul, died from drowning yourself in a lake. He hummed.

"... I'll give you a second chance, but in a different way." he took the pocket watch, reversing time for a couple seconds to save you from dying... "I'll be there to save you before your clock strikes death."