Grenzo, Dungeon Warden | The Cauldron of Eternity | Phyrexian Altar

(and two other cards)

Cast
Dark Ritual by paying ({B} magic symbol) , adding ({B} magic symbol) ({B} magic symbol) ({B} magic symbol) .
Activate
Phyrexian Altar by sacrificing
Greenwarden of Murasa, adding one mana of any color.
When
Greenwarden of Murasa dies,
The Cauldron of Eternity triggers, putting
Greenwarden of Murasa from your graveyard onto the bottom of your library.
Activate
Grenzo by paying ({2} magic symbol) , putting
Greenwarden of Murasa from the bottom of your library into your graveyard, and then putting it onto the battlefield.
When
Greenwarden of Murasa enters the battlefield, it triggers, returning
Dark Ritual from your graveyard to your hand.
Repeat.
Once you have infinite mana, you may activate
Grenzo's ability any number of times.

Infinite colored mana.
Infinite death triggers.
Infinite ETB.
Infinite LTB.
Infinite magecraft triggers.
Infinite sacrifice triggers.
Infinite storm count.
Put all creature cards with power less than or equal to
Grenzo's from your library onto the battlefield.