If only one of the philosophers is scum, I would expect it to be Socrates. If both Plato and Socrates are scum, you'll all probably want to kill me too, but I can assure you that that would be a mistake.

I'm always a little suspicious of Isaac, and Agamemnon is a bit scummy as a character, but the same could be said for Medea and she's our doctor.

Lots of other characters could be scum too. Pericles pretty much single-handedly brought about the downfall of Athens.

Odysseus acted against the gods, and earned the personal enmity of Helios and Poseidon, and maybe others.

If anyone was lying in their claims, I still think it might be you. The Beloved role is absolutely perfect for a scummer to hide behind. I still wouldn't want to vote for you though; it's too big a risk.

Of the three on your list, I'd go with Stephen, but I'd still like to hear more first, like maybe a roleclaim.