Times Silent Keeper
Being made of Light, you can't kill it with Light. Trying to do so will only make it stronger. It's like trying to kill Artix by making horrible puns.
This status works similarly to Mana Shield, except that it has negative efficiency. While active, all Light based attacks will heal MP instead of damage HP. This Mana Shield can only prevent a certain amount of damage - this is its Power. Once the shield runs out of Power, the status ends.
Entry thanks to kamikazi008 and In Media Res.