Netherese Battle Curse( Lost Empires of Faerun, p. 8)
You can channel your own arcane energy into a powerful curse upon those who dare to face you in battle.
By giving up an arcane spell slot or prepared spell before making an attack roll, you can perform a battle curse as a melee attack. You gain a bonus on the attack roll equal to the level of the spell or spell slot so sacrifi ced. If your attack hits, the target must succeed on a Will save (DC 10 + level of spell or slot expended + your Cha modifi er) or take a -2 penalty on attack rolls, saving throws, ability checks, skill checks, and weapon damage rolls for 1 minute. The effects of multiple battle curses don't stack, and any foe that successfully resists your battle curse cannot be affected by it again for 24 hours. Any effect that dispels or removes a curse eliminates the battle curse. Your caster level equals your character level for this purpose.