Activate Xerex Strobe-Knight by tapping it, creating a 1/1 Knight creature token.
When the Knight enters the battlefield, Intruder Alarm triggers, untapping all creatures.
Repeat.

Infinite creature tokens

Infinite creature ETB

Infinite mana creatures you control can produce

Infinite untap of creatures

Xerex Strobe-Knight

Intruder Alarm

Activate Xerex Strobe-Knight by tapping it, creating a 1/1 Knight creature token.
Activate Ashnod's Altar by sacrificing the Knight, adding {C}{C}.
When the Knight dies, Xerex Strobe-Knight triggers, untapping it.
Repeat.

Infinite colorless mana

Infinite death triggers

Infinite creature LTB

Infinite creature sacrifice triggers

Thornbite Staff

Ashnod's Altar

Activate Xerex Strobe-Knight by tapping it, creating a 1/1 Knight creature token.
Activate Phyrexian Altar by sacrificing the Knight, adding one mana of any color.
When the Knight dies, Xerex Strobe-Knight triggers, untapping it.
Repeat.

Infinite colored mana

Phyrexian Altar

Activate Xerex Strobe-Knight by tapping it, creating a 1/1 Knight creature token.
Activate Altar of Dementia by sacrificing the Knight.
When the Knight dies, Xerex Strobe-Knight triggers, untapping it.
Resolve the Altar of Dementia ability, causing target player to mill cards equal to the Knight's power.
Repeat.

Infinite mill

Infinite self-mill

Altar of Dementia

Combos with "Xerex Strobe-Knight"