This is a variation of the Spook spell, modified to affect multiple opponents, but not allies.

Terror (-0 to Fright Check, Sight-Based) [15] 
    Selective Area [+20%] 
    Hearing-Based [-20%] 
    Magical [-10%] 
    Spell Components [-40%] 
        Must hold hands up 
        Must make a loud, scary sound 
        Must wear a scary-looking mask 
Levels 2+ [+5/level] 
    Increase Fright Check penalty by 1 [+10 base]