Fortunately for everyone present Alida doesn't have that sense to try something just to see what it does. At least not with the blood.
She's actually doing something that amounts to brain surgery, with a blunt force object. Swing once and she dents the skull; swing twice and there is enough damage to keep it down, at least for a moment and the third time's a charm.
"It matters. If it's a Necromancer we have to stop them. If it is something else then I am not sure." Alida is not anyone's idea of battle-ready, sorry to say. She's not doing much to help Grave with his...cleaning task, though, deciding instead to stick near Marc. Because if one of those things reaches him there will be hell to pay.