Although Connor Mac|Intyre plays Phelan brillitantly, I don't see how the character can stay around much longer.
The character is emotionally dead.
Vinny isn't his mate - he's just someone he can team up with to con people. He has no friends.
He has no feelings for Eileen - she's just someone to satisfy his needs and give him somewhere comfortable to live. In fact he has no feelings for anybody.
He has no concerns about ruining people financially.
He's quite willing to blackmail.
He has no sense of family.
He has no conscience about anything, including life and death.
He's only interested in his own wellbeing and will use anyone to that end.
A few have realised just what he is, and eventually they all will.