Alchemical Phantom Strike

As part of the action used to cast this spell(It still counts for a two-weapon fighting bonus action.), you weave a sudden minor illusion (a puff of colored smoke or a hissing sound) that distracts a creature within 5 feet, granting you advantage on your next melee attack roll against it this turn. Simultaneously, your alchemical component vaporizes into a temporary caustic coating on your blade.

You then immediately make a melee weapon attack with a Finesse or Light weapon against that target. On a hit, the target takes the weapon's normal damage, and the alchemical vapor flares up: the target takes an extra 1d4 Acid or Poison damage (your choice on hit) and cannot take Reactions until the start of its next turn. Additionally, the target gains the [conditions]Blinded[/conditions] condition relative to all creatures other than you until the end of your turn.

Cantrip Upgrade: The alchemical catalyst grows more potent at higher levels. The extra acid/poison damage increases by 1d4 when you reach level 5 (2d4), level 11 (3d4), and level 17 (4d4).