Can be combined with Constitution skill for a significant health point bonus.
Likewise, combined with the Spell Resistance skill will result in an extremely high resistance to spells.
Choosing mod 1A Rejuvenation will give a huge hitpoint regeneration bonus, so the player can take a high amount of damage without losing life; and combining it with mod 3b Safeguard the Shadow Warrior will be almost invincible against physical damage.
Note that, like all CA's in the Death Warrior aspect, casting speed is determined by weapon speed, and can be boosted by weapon lore skills and +% attack speed. Likewise, the casting speed will be penalized by wielding a weapon with too high a level.
Pros and Cons
Great life and willpower bonuses
Regen penalty is very low for a buff, and can be further reduced by the Discipline mod