I unno, I was just brain storming really and kind of wondering why they just don't let Spirits Within return MP by half based on the damage it dealt when used in a combo? Poke a mob in the crotch for 600, get 300 MP back. Yay a free Holy Succor every 60 seconds or something like that... Would probably solve their MP issues I would think... Or they could nail the real problem here like everyone else has said. Make defense actually mean something or give them an HP boost.
If Divine Veil is 100% frontal attacks being blocked for 20s, that combined with Outmanouver looks to be a fairly good sanguine rite replacement.