It saves against 90% of the spells in the game.
Quote:
[Skills help] evasion
Automatic
Evasion allows the target of an ability that normally allows a saving throw
for half damage to instead make a saving throw for no damage. The list of
abilities currently eligible for evasion include: acid blast, bolt of glory,
burning hands, call lightning, chain lightning, chill touch, color spray, cone
of cold, energy drain, fireball, flame strike, hellfire, lightning bolt, magma
spray, shocking grasp, spear of faith, tenebrious burst, vampiric touch,
acid breath, fire breath, frost breath, gas breath, and lightning breath.
See also: 'saving throw'
This wouldn't be bad if every caster got a fort/will/reflex spell.
Now rereading it it does look like reflex saves. There seemed to be finger of death and petrification on the list last I looked.