Heel-Cutter
When you hit a creature with an attack using a Melee weapon or an Unarmed Strike, you can expend one Battle Die as a Bonus Action to prevent the target from escaping. Add the Battle Die to the attack’s damage roll. The target must succeed on a Strength saving throw or its Speed becomes 0 until the end of its next turn.
Sources
Valda’s Spire of Secrets Extras (2024)