Scholar of New Horizons, Intruder Alarm, Kithkin Spellduster, and Ashnod's Altar

Prerequisites

• Scholar of New Horizons on the battlefield
• Intruder Alarm on the battlefield
• Kithkin Spellduster on the battlefield
• Ashnod's Altar on the battlefield
• Scholar of New Horizons does not have summoning sickness

Steps

1. Activate Ashnod's Altar by sacrificing Kithkin Spellduster, adding
2. Kithkin Spellduster dies, triggering its persist ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Kithkin Spellduster enters the battlefield, triggering Intruder Alarm, untapping all creatures
4. Activate Scholar of New Horizons by tapping it and removing the -1/-1 counter from Kithkin Spellduster, causing you to search your library for a Plains card and either put it onto the battlefield or put it into your hand
5. Repeat

Results

• Infinite colorless mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite sacrifice triggers
• Infinite untap of all creatures
• Put all Plains cards from your libary into your hand