Jan Jansen, Chaos Crafter + Haunted One + Retribution of the Ancients + Blasting Station
Infinite Mana: Infinite LTB, Infinite ETB, Infinite colored mana, Infinite sacrifice triggers, Infinite death triggers, Infinite damage, Infinite Treasure tokens, Reduce the toughness of creatures opponents control to 0, Infinite power for certain creatures until end of turn
Activate Jan Jansen's first ability by tapping it and sacrificing another artifact creature you control except the Gnome or Artificer.
Jan Jansen triggers, causing it and creatures you control that share a creature type with it to get +2/+0 and undying until end of turn.
Resolve the Jan Jansen ability, creating two Treasure tokens.
Activate Blasting Station by tapping it and sacrificing Jan Jansen.
When Jan Jansen dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
When Jan Jansen enters the battlefield, Blasting Station triggers, untapping Blasting Station.
Resolve the Blasting Station ability from step 4, dealing 1 damage to any target.
Activate Jan Jansen's first ability by tapping it and sacrificing the Gnome or Artificer.
When the Gnome or Artificer dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
When the Gnome or Artificer enters the battlefield, Blasting Station triggers, untapping Blasting Station.
Resolve the Jan Jansen ability, creating two Treasure tokens.
Activate a Treasure by tapping and sacrificing it, adding {B}.
Activate Retribution of the Ancients by paying {B} and removing the +1/+1 counter from Jan Jansen and the other Gnome or Artificer, giving a creature -2/-2 until end of turn.
Repeat from step 4.
Cards: Jan Jansen, Chaos Crafter, Haunted One, Retribution of the Ancients, Blasting Station