Intruder Alarm + Maskwood Nexus + Karn, Silver Golem

Intruder Alarm

Maskwood Nexus

Karn, Silver Golem

How it works

1. Activate Karn by paying 1, causing Maskwood Nexus to become a 4/4 artifact creature until end of turn.
2. Activate any number of mana-producing creatures you control by tapping them, adding at least 3.
3. Activate Maskwood Nexus by paying 3 and tapping it, creating a 2/2 Shapeshifter creature token.
4. When the Shapeshifter enters the battlefield, Intruder Alarm triggers, untapping all creatures.
5. Repeat from step 2.
6. If creatures you control can tap to produce at least 4, this combo nets infinite mana.

This ingenious loop transforms your mana base into a self-sustaining engine by turning Maskwood Nexus into a living creature via Karn, Silver Golem's ability. Because Maskwood Nexus is now a creature, every time you crack its activation using the mana generated by your creatures, the newly spawned Shapeshifter token immediately triggers Intruder Alarm. Thanks to Maskwood Nexus's passive changeling-bestowing effect, even non-token creatures you control are folded into the synergy, allowing them to instantly untap and fuel the loop anew.