Curse of the Despot

Tyranny stands opposed to justice and despots are cursed to meet a grisly end.  As a bonus action, you imbue your weapon with a powerful curse.  On the next successful hit (during your turn) you transfer the curse to the target, causing spectral daggers to appear.  The target must then succeed on a Constitution (Con) Saving Throw or take 6d10 piercing damage or half on a success.  If the curse does not transfer by the end of your turn, take 1d10 piercing damage as the curse backfires.