Thorny Vines

The Rose Heart: +1 rapier. Once per day, on a successful hit, the user can cause thorny vines to erupt from the wound, inflicting an additional 4d4 piercing damage. If the additional damage is over 8, the creature must also make a strength check (DC 14) or they are considered grappled. They may remake the check at the beginning of their turn each time. For each round they remain grappled they take an additional 1d4 piercing damage at the end of their turn.