As Diablo1008 suggested, train in death up to feint and Ice up to tower shield. Also make sure to get the spirit blade and spirit trap from Niles at the krokosphinx in krokotopia. You can also get reshuffle from the trainer in Colossus.
As a Grandmaster in Life, I used my training points this way and still have 2 or 3 unused points.
Many people will suggest training in storm to offset the low damage of Life. What you must remember is that at high levels you seldom cast out of school damage spells. (I know I don't). Without traps or blades and wearing all my grandmaster gear, my centaur will do almost 800 damage. Add a feint to that along with blades and traps, you can easily do enough damage to put a sizable dent in a boss's health, and if the boss is death--it will more than likely kill them. As I have been known to say while battling the death minions with Malistaire. Trap + Centaur = dead.