SPELL_MANASHIELD

Usage       : cast manashield
Accumulative: No
Duration    : 3 ticks
Level       : Level 19+ current class mage only.
Mana Usage  : 7

When in effect, a manashield will take all of the damage towards your mana
instead of hit points. The damage done to mana is 1 to 2 times what would
have been taken away from hit points. Once your mana reaches 1/3 of maximum
mana possible, the spell will dissipate.

This spell and its effects are known to be neutralized by the malediction spell.

See also:  MAGE MANA MANASHIELDDROP