Hex Vulnerability

The targeted creature becomes susceptible to a repeat use of your harmful hexes, even if you could not otherwise target that creature with a particular hex for a certain time period. For example, normally after you target a creature with a charm hex, you cannot target it again for 1 day. But after casting this spell on a creature, you could try the charm hex repeatedly as long as the spell persists. The end of this spell has no effect on any active or ongoing hex on a creature. For example, if the creature failed its save against a second use of your charm hex, it remains charmed for the normal duration, even if the spell expires before the hex does. Each subsequent casting of this spell on a target within a 24-hour period gives the target a +4 bonus on its save against the spell and imposes a -4 penalty on your caster level check to overcome the target's spell resistance with this spell.