Since I'm building a McMourning crew, and this is the place for information on the good doctor, I thought I'd ask here:
Since sacrificing a body part gives McMourning "Fast", my assumption is that you can only take advantage of this ability once per activation. I've heard (and probably misinterpreted) the idea that McMourning can slice, gain a counter, use fast to slice again, gain a counter, slice again, etc., but I don't know how true that is.
I might actually take him to the table this week, so answers would be great before I accidentally abuse him.