Zardnaar
Legend
It is not the damage, it is the frightened condition that you are after with it and they get disadvantage on the save against it after level 10. Further if you hit them at least once every round they keep getting disadvantage on the save to break it.
Frightened is extremely powerful because of the movement restrictions and in one-on-one melee combat it effectively eliminates extra attack, reducing enemies to one attack a round, burning a reaction to do it and making that attack with disadvantage. You hit the enemy, frighten it, then back up (taking an AOO) and the bad guy can't move into attack you on its turn.
Hmmn. How does it compare to hex though? Say at level 4 think I would take that.
By 8 warcaster and fae/shadow touched so maybe both?