Oathbow

Once per day the target of your attack becomes
your sworn enemy until it dies or until dawn
seven days later. You have advantage on rolls
against your sworn enemy. They gains no benefit
from cover, except total cover, and you suffer no
disadvantage due to long range. Deal extra 3d6
piercing damage on hit.
{c}1d8 Piercing; Range: 150/600; Two-Handed
Swift death to you who have wronged me.