Heartstone + Soulbright Flamekin + Deadeye Navigator + Signpost Scarecrow

Heartstone

Soulbright Flamekin

Deadeye Navigator

Signpost Scarecrow

How it works

1. Activate Soulbright Flamekin 3 times paying 1 each time, adding eight with the third activation.
2. Activate Signpost Scarecrow 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.