I think there will be several "optimal" plays of Scapegoat.
1. You don't have a great blocking option for your opponent's next turn. Obviously you have an EC (Scapegoat), but if you have nothing to support him, just banish him during your discard phase to stall a turn.
2. It's the opponent's turn and you don't have a great rescue option for your next turn (and you're unlikely to draw into one). Banish Scapegoat during your opponent's discard phase and stall a turn.
3. It's the opponent's turn and he has no Lost Souls available for your next turn. If you don't think you'll be able to generate one, banish Scapegoat during his discard phase and make sure he doesn't get ahead of you in terms of attacks.
4. You just got to 4, but you need Son of God (or TSC) to win and it is still in your deck. Banish Scapegoat during your discard phase to ensure your opponent can't catch up and giving you another draw phase before they can attack again.
Not to mention that you have 2 ECs to tutor Scapegoat (Esau and Nebby), and if Scapegoat happens to get negated in territory before you decide to banish him, Esau can discard him to get value through a draw 2.
This is all in addition to the good side...so much versatility.
