Haunted One
Retribution of the Ancients
Phyrexian Altar

   Prerequisites

What do I need to start this combo?
All permanents on the battlefield.
Jan Jansen must be your commander.
Jan Jansen and the additional Gnome or Artificer do not have a +1/+1 counter on them. You control at least one additional artifact creature.

   Steps

How does this combo work?
1
Activate Jan Jansen's first ability by tapping it and sacrificing another artifact creature you control except the Gnome or Artificer.
2
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.
3
Resolve the Jan Jansen ability, creating two Treasure tokens.
4
Activate Phyrexian Altar by sacrificing Jan Jansen, adding .
5
When Jan Jansen dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6
Activate Jan Jansen's first ability by tapping it and sacrificing the Gnome or Artificer.
7
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.
8
Resolve the Jan Jansen ability, creating two Treasure tokens.
9
Activate Retribution of the Ancients by paying and removing the +1/+1 counter from Jan Jansen and the other Gnome or Artificer, giving a creature -2/-2 until end of turn.
10
Repeat from step 4.

   Results

What do I get from this combo?
Infinite LTB
Infinite ETB
Infinite colored mana
Infinite sacrifice triggers
Infinite death triggers
Infinite Treasure tokens
Reduce the toughness of creatures opponents control to 0
Infinite power for certain creatures until end of turn