Hopefully he doesn’t have you listed as executor of his will. That would be a cruel joke. Dealing with closing out an estate is time consuming and can be expensive depending on the estate. Honestly might check on that. You can file with the court to refuse, but again, that puts the burden on you to do so.

Otherwise, there is no reason for continuing contact. You know you cannot be friendly without him pulling you back in again. He’s very good at that. No contact is your clear boundary for your future sanity. You don’t have to ever speak again.