Loporrit Scout + Sinking Feeling + Ashnod's Altar + Splinter Twin

Loporrit Scout

Sinking Feeling

Ashnod's Altar

Splinter Twin

How it works

1. Activate Loporrit Scout by tapping it, creating a creature token.
2. When the creature token enters the battlefield, Loporrit Scout triggers, giving Loporrit Scout +1/+1 until end of turn.
3. Acitvate Loporrit Scout by paying 1 and putting a -1/-1 counter on it, untapping it.
4. Activate Ashnod's Altar by sacrificing the creature token, adding CC.
5. Repeat.

This ingenious loop relies on turning Splinter Twin into a self-contained, self-untapping engine by enchanting Loporrit Scout. Normally, the copy ability requires tapping, but Sinking Feeling grants the Scout an activated ability that untaps it for `{1}` and a `-1/-1` counter—a cost easily offset by the temporary `+1/+1` pump triggered whenever the newly spawned token enters. As you repeat this process, Ashnod's Altar steps in to sacrifice the hasty token for `{C}{C}`, generating a net surplus of colorless mana while fueling the entire sequence indefinitely.