Panoptic Mirror, Strionic Resonator, Ghostly Flicker, and Grim Monolith
Here's how the cards Panoptic Mirror, Strionic Resonator, Ghostly Flicker, and Grim Monolith results in Infinite LTB, Infinite ETB, Infinite colorless mana, Infinite storm count, Infinite magecraft triggers, Infinite landfall triggers, Infinite blinking of permanents you control, and Infinite mana permanents you control that enter the battlefield untapped can produce

Panoptic Mirror

Strionic Resonator

Ghostly Flicker

Grim Monolith