Mikaeus, the Unhallowed + Cryptic Trilobite + Skullclamp

Mikaeus, the Unhallowed

Cryptic Trilobite

Skullclamp

How it works

1. Activate Cryptic Trilobite's first ability by removing a +1/+1 counter from it, adding CC that can only be spent to activate abilities.
2. Repeat step 1 until Cryptic Trilobite does not have any +1/+1 counters on it.
3. Activate Skullclamp's equip ability by paying 1, attaching it to Cryptic Trilobite.
4. Cryptic Trilobite dies as a state-based action due to having zero toughness, triggering its undying ability and Skullclamp.
5. Resolve the Cryptic Trilobite trigger, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Skullclamp trigger, causing you to draw two cards.
7. Repeat.

This ingenious loop turns Skullclamp's lethal toughness reduction into an engine of endless rebirth, utilizing Mikaeus, the Unhallowed to grant undying to non-Human creatures like Cryptic Trilobite. By spending Cryptic Trilobite's stored energy to activate Skullclamp's equip cost, you send the Trilobite directly to the graveyard where its undying ability rescues it—returning it with a fresh +1/+1 counter while Skullclamp rewards your sacrifice by drawing you two cards. Rinse and repeat to churn through your entire deck while generating a massive reserve of restricted colorless mana to fuel any other abilities you desire.