[Taqwus]

Hm. Clams are always nice. But for Celestial Masters, Theurgs, Mystics and others, it'd be nice to get some battlefield use.
BoW mixes decently with most undead; I think either Soulless or Ghouls might not be immune, but all the longead, spectral and wightly ones are. Jotuns also are immune, although Utgard needs to be careful about the Seithkonas that are oh so fun once Nether Darts is available.
A water mage can still be useful on the battlefield, with Quickening, Cold Bolts, Falling Frost, Frozen Heart, warding... not as showy as fire or lightning magic perhaps, or as entertaining as Gifts from Heaven (150 points of *WHAM!*) but still handy.