Blightbeetle + Woe Strider + Harmless Offering

Blightbeetle

Woe Strider

Harmless Offering

How it works

1. Donate Blightbeetle to an opponent
2. Activate Woe Strider by sacrificing the undying creature.
3. When the undying creature dies, its undying ability triggers, returning itself from your graveyard to the battlefield without a +1/+1 counter on it due to Blightbeetle.
4. Resolve the Woe Strider ability.
5. Repeat from step 2.

By using Harmless Offering to hand over Blightbeetle to your opponent, you completely weaponize its static ability so that it prevents your adversaries' creatures from ever receiving +1/+1 counters. With this negative shield locked onto their side of the board, an undying creature can be sacrificed to Woe Strider over and over again without ever accumulating the counter that would normally shut its trigger down. This creates an infinite loop of deaths, entries, and sacrifices, all while Woe Strider lets you scry through your entire deck to find your finishing piece.