No summary for Pieta can anyone help?

This is the summary Lezhin has for Pieta, it's pretty surface level but:

""Dante has lived his life hiding a secret—he is immortal. Working as a repairman, he one day witnesses a murder at the home of his client, Demis. Instead of running, he makes an unusual request: Kill me.

Demis refuses at first, but upon discovering Dante’s immortality, he becomes intrigued. A dangerous promise is made—one that ties them together in a fate neither of them could have foreseen.""

Ooooooor were you looking for a more in depth summary with spoilers?? :)

Thank you I guess green flag or black flag? Any abuse, rape or things to avoid?

Oh my... so Demis is a black flag that somewhat mellows out, but this series is incredibly graphic when it comes to gore and abuse, especially in the beginning.