Heartstone + Soulbright Flamekin + Deadeye Navigator + Stonework Packbeast

Heartstone

Soulbright Flamekin

Deadeye Navigator

Stonework Packbeast

How it works

1. Activate Soulbright Flamekin 3 times paying 1 each time, adding eight with the third activation.
2. Activate Stonework Packbeast for 1 to add .
3. Pay to activate the ability granted to Soulbright Flamekin by Deadeye Navigator, blinking it.
4. When it ETBs, pair it with Deadeye Navigator.
5. Repeat this process for infinite mana.
6. If you have another creature with an ETB, you can flicker Deadeye and pair it to that creature, then flicker that creature infinite times.