Treacherous Weapon

Level: Bard 1, hexblade 1, sorcerer/wizard 1
Components: V, S
Casting Time: 1 immediate action; see text
Range: Close (25 ft. + 5 ft./2 levels)
Target: One creature
Duration: 1 round
Saving Throw: Will negates
Spell Resistance: Yes

You make a gesture accompanied by a sharp arcane command, and your foe’s weapon gives off a momentary shower of sparks.

You can cast this spell on any creature wielding a manufactured weapon. If the target fails its saving throw, the weapon
takes a –1 penalty on attack rolls and damage rolls. For every two caster levels beyond 1st, the penalty worsens by 1. Thus, at 3rd level, the weapon takes a –2 penalty; at 5th level, a –3 penalty; at 7th level, a –4 penalty; and at 9th level or higher, a maximum –5 penalty.
When this spell is cast on a creature wielding a magic weapon, subtract the weapon’s enhancement bonus from the penalty. For example, a 1st-level caster would reduce a +1 longsword to a +0 longsword.

If you extend the spell’s casting time to 1 standard action, the enhancement penalties double.