Maxperson
Morkus from Orkus
The way the spell reads you only use up the blood if you draw the circle with it. Realistically, though, how often are you going to be casting that spell in a 24 hour period such that 1) your vial isn't hasn't hit its expiration date, and 2) the humanoid killed didn't have enough blood for 326153 small vials, so you only have 1?It’d be pretty hard to interpret it any other way, since that’s exactly what it says.
Yeah, I think that’s the best interpretation. The spell can be cast in a way that doesn’t consume the component, or in a way that does. If you want to cast it in the way that does consume the component, then you need the actual component for it to consume. It’s practically tautological.
Yeah, I this is a far weaker argument, and IMO doesn’t hold up.
The second consideration is that if you don't bind it within the circle, the odds are very good that it will soon escape and start eating peoples faces for 1d6 rounds.