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

Infinite colorless mana

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite mana creatures you control can produce

Infinite sacrifice triggers

Put all Plains cards from your libary into your hand

Infinite untap of all creatures

Scholar of New Horizons

Intruder Alarm

Glen Elendra Archmage

Ashnod's Altar

Activate Phyrexian Altar by sacrificing Glen Elendra Archmage, adding one mana of any color.
Glen Elendra Archmage dies, triggering its persist ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Glen Elendra Archmage enters the battlefield, triggering Intruder Alarm, untapping all creatures.
Activate Scholar of New Horizons by tapping it and removing the -1/-1 counter from Glen Elendra Archmage, causing you to search your library for a Plains card and either put it onto the battlefield or put it into your hand.
Repeat.

Infinite colored mana

Phyrexian Altar

Activate Ashnod's Altar by sacrificing Kithkin Spellduster, adding {C}{C}.
Kithkin Spellduster dies, triggering its persist ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Kithkin Spellduster enters the battlefield, triggering Intruder Alarm, untapping all creatures.
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.
Repeat.

Kithkin Spellduster

Activate Phyrexian Altar by sacrificing Kithkin Spellduster, adding one mana of any color.
Kithkin Spellduster dies, triggering its persist ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Kithkin Spellduster enters the battlefield, triggering Intruder Alarm, untapping all creatures.
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.
Repeat.

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

Lesser Masticore

Activate Phyrexian Altar by sacrificing Lesser Masticore, adding one mana of any color.
Lesser Masticore dies, triggering its persist ability, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Lesser Masticore enters the battlefield, triggering Intruder Alarm, untapping all creatures.
Activate Scholar of New Horizons by tapping it and removing the -1/-1 counter from Lesser Masticore, causing you to search your library for a Plains card and either put it onto the battlefield or put it into your hand.
Repeat.

Combos with "Scholar of New Horizons"