Cerberus Vae III. While not hard, it's become tedious, even as a remix. I also played it a lot year 1, so that probably has something to do with it too. I'm one of those people who like the Undying Mind strike, but only if I have a competent team (on higher difficulties). If I'm paired with players that are dying every other minute, I'll bail; it's a waste of my time. S.A.B.E.R. is cool too, now that I have the sequence down and I'm not dying by sniping Shanks unexpectedly.