Shadow brand has the Leeching Darkness effect. I don't know if this is lifedrain, but I do know that it affects more than one square, so it's possible to kill your own commander with it... I lost one of EA Ulm's war chief's (or whatever they're called... the warrior/general recruitable commander) to his own sword
My shadow brand queston would be: Are undead immune to this effect? I'd expect them to be, but it might be worth checking before I play Ermor...