At the beginning of your end step, Jon Irenicus triggers, giving control of Ronom Serpent to an opponent who controls no snow lands.
When Ronom Serpent's controller controls no snow lands, Ronom Serpent triggers, causing them to sacrifice it.
However, Ronom Serpent cannot be sacrificed due to its ability.
Ronom Serpent triggers again, creating a mandatory infinite loop that causes the game to end in a draw.

Draw the game

Jon Irenicus, Shattered One

Ronom Serpent

If needed, give control of Ronom Serpent to an opponent who controls no snow lands.
When Ronom Serpent's controller controls no snow lands, Ronom Serpent triggers, causing them to sacrifice it.
However, Ronom Serpent cannot be sacrificed due to Assault Suit.
Ronom Serpent triggers again, creating a mandatory infinite loop that causes the game to end in a draw.

Combos with "Ronom Serpent"