Control Blight

Target one blight infected creature and make a arcana check (DC set by DM on a situational basis starting from DC10) if the target passes the check the caster will take 4 d4 psychic damage from the backlash. If attempted multiple times on same target the check is at disadvantage the second time and the target is immune on the 3rd attempt. 

You have a telepathic link with the Charmed target while the two of you are on the same plane of existence. On your turn, you can use this link to issue commands to the target (no action required), such as “Attack that creature,” “Move over there,” or “Fetch that object.” The target does its best to obey on its turn. If it completes an order and doesn’t receive further direction from you, it acts and moves as it likes, focusing on protecting itself.

You can command the target to take a Reaction but must take your own Reaction to do so.

Using a Higher-Level Spell Slot. You are able to make the DC check easier by using higher level spell slots