Weakness

You shatter a glass orb into your own chest, and extend your hand outwards towards a creature. A glowing aura (of your choosing) appears around you, before shooting through the air at the target.  The target creature must make a CON saving throw against your spell DC.  If it fails, you may choose up to one damage type for that creature to have acquire vulnerability.  However, you become vulnerable to that same damage type, while the creature is effected.  If the target creature succeeds, the spell fails.