SHRIEK (Air)
You make a thorough search of all related material, but you only find one reference to the spell. The text mentions in passing that the spell is a high level combat spell of Air, involving a sonic attack of some sort.

Requirements
Caster Realm: Air
Caster Level: 20
Spell Point Cost: 33
Spell Energy: Air
Spell Component: None

Restrictions

This spell may not be cast in “no combat” areas and puts the caster on the combat timer.

This spell may be directed at a specific target.

Casting
SingleAttack
Secret Number 1: 150
Secret Number 2: 200

Example
Ione casts shriek on Evia.

Failure

Success
Ione spends 33 spell points to cast the spell.
Ione sees: The winds howl in deafening rage at Evia for %u points!
Others see: Ione calls up a sonic attack, deafening Evia!

Magic Number: 92