[quote=@IncredibleBee] Okay but why doesn't it have leftover prana to do that one more time? [/quote] Explaining that requires explaining certain actions of the Second Owner during the past seventy years, which I can't explain because that's a plot spoiler. [quote=@KoL] What you guys are saying isn't impossible, IMO. But would only make sense for an Avenger Class Servant to be summoned in such a way. [/quote] Summoning Avenger still means summoning a Servant, even if he's shit, so it hits the same wall.