2 monsters
If this card is Link Summoned using 2 DARK monsters with different names as material, it gains this effect.
• You can Tribute 1 monster, then target 1 face-up card on the field; place 1 Patrol Counter on it. You can only use this effect of Beat Cop from the Underworld once per turn. (If a card with a Patrol Counter would be destroyed by battle or card effect, remove 1 Patrol Counter from it instead.)