Assassin's Mark

You mark a living being for certain death. Choose a creature within range that you can see. That creature must succeed on a Constitution Saving Throw or become marked. For the duration or until the spell ends, the next Critical Damage that you score against the creature is increased by a single damage dice for every source of damage of the triggering attack.

For each level of spell slots used to cast this spell beyond 1st, increase the range by 20ft and the duration by 1 minute.