RE: the sickle
Yes, so the Wraith Lord in question was apparently scripted to <Soul Vortex, attack, Shadow Blast, attack, Shadow Blast, attack rearmost> or something similar, with the logic being that with boots of flight, an <attack> would move right into the thick of the enemy for a point-blank Shadow Blast, and that ending on "attack" meant the Wraith Lord would collect enough gems to repeat the sequence next turn.
I'm a little leary, myself, of letting anyone cast gem-hungry spells before going into melee, since they have such high fatigue costs (the Wraith Lord is going to be taking 40+ fatigue from each casting even with maximum death gems), but I guess it must have worked out okay.
-Max