It's Boros allies and equipment for SOI standard. Kor Bladewhirl, Firemantle Mage, and Lantern Scout provide great, cheap rally triggers with other cards like Expedition Envoy, Mikindi Aeronaut, and Captain's Claws.

The equipment aspect of this deck is largely enabled by Weapons Trainer and Stone Haven Outfitter. Bone Saw can easily and quickly enable their abilities. Captain's Claws is not just another cheap way to benefit from the Trainer and the Outfitters abilities, but will also allow you to trigger rally every combat phase.

Nahiri, the Harbringer is cycling, removal, and tutoring all in one. Since her -8 only leaves it out for one turn, you can trigger rally multiple times with the same creature. Stoneforge Masterwork is a great target for her -8 as well.

Any constructive criticisms are welcome in the comments.