So we can't turn people into eels, okay. Well. There's likely some form of transformation magic they could learn that they could use to turn people into eels, but they wouldn't be magic battery eels.

Sure Lucifer was against sushi, but if it was energizing sushi...

Eh.

That's what the Ikorr sap is for.

Mm. The celestial makeup of our existence, different levels of potency depending on your classification. It'll... recharge. On it's own. Eventually. For him. Castiel's likely to die first.