Arcbound Reclaimer + Showdown of the Skalds + Experimental Frenzy + Dark Sphere

Arcbound Reclaimer

Showdown of the Skalds

Experimental Frenzy

Dark Sphere

How it works

1. Cast Dark Sphere from the top of your library by paying 0
2. Showdown of the Skalds triggers, putting a +1/+1 counter on Arcbound Reclaimer.
3. Activate Dark Sphere by tapping and sacrificing it.
4. Activate Arcbound Reclaimer by removing a +1/+1 counter from it, putting Dark Sphere from your graveyard onto the top of your library.
5. Repeat.

This clever little loop turns the top of your library into an endless engine by leveraging the casting restrictions of Experimental Frenzy. With Experimental Frenzy letting you cast spells directly from the top, you can continuously deploy Dark Sphere for zero mana. Each time you cast it, Showdown of the Skalds triggers its second and third lore chapters to feed a +1/+1 counter back onto Arcbound Reclaimer. That counter is then immediately spent to activate Arcbound Reclaimer, recycling Dark Sphere right back onto the top of your library so the entire process can begin anew.