Blightcaster

Creature — Human Wizard

Whenever you cast an enchantment spell, you may have target creature get -2/-2 until end of turn.

2/3

2013-07-01:
Blightcaster’s ability will resolve before the enchantment spell that caused it to trigger.
2013-07-01:
If you are the only player who controls a creature when Blightcaster’s ability triggers, you must choose one as the target, although you can choose not to give it -2/-2.
2015-06-22:
If you are the only player who controls a creature when Blightcaster’s ability triggers, you must choose one of those creatures as the target, although you can choose to not give it -2/-2.