Yenna, Redtooth Regent + Chatterfang, Squirrel General + Ashnod's Altar + Phantatog

Yenna, Redtooth Regent

Chatterfang, Squirrel General

Ashnod's Altar

Phantatog

How it works

1. Activate Yenna by paying 2 and tapping it, creating a token copy of an Aura you control and a 1/1 Squirrel creature token, then untapping Yenna and causing you to scry 2.
2. Activate Ashnod's Altar by sacrificing the Squirrel, adding CC.
3. Activate Phantatog's first ability by sacrificing the Aura token, giving Phantatog +1/+1 until end of turn.
4. Repeat.

This clever loop puts Yenna, Redtooth Regent at the center of a self-sustaining enchantment-replication engine, where her ability to copy an Aura triggers Chatterfang, Squirrel General's replacement effect to spawn an accompanying Squirrel token alongside the copy. Ashnod's Altar then provides the necessary mana to fund Yenna's activation by converting that sacrificial Squirrel into raw colorless energy, while Phantatog neatly disposes of the newly minted Aura token to fuel its own pump ability and clear the board for the next iteration. Because Yenna untaps whenever she successfully copies an Aura, you can continuously repeat this cycle to harvest endless creature entries, exits, and sacrifices while scrying through your entire library.