Doppelgang by paying ({6} magic symbol) ({G} magic symbol) ({U} magic symbol) , creating two token copies of
Omnath and
Mystic Sanctuary.
Put all but one of the newest
Omnath tokens into your graveyard due to the legend rule.
Each
Mystic Sanctuary token created triggers, each
Omnath you controlled prior to step 2's second abilities trigger twice, and each of the created
Omnath token's first abilities trigger once.
Resolve both
Mystic Sanctuary abilities, putting
Doppelgang and up to one other instant or sorcery from your graveyard onto the top of your library.
Resolve both
Omnath tokens' first triggers, causing you to draw two cards, including
Doppelgang.
Resolve the remaining
Omnath triggers, causing you to gain 8 life, add ({R} magic symbol) ({R} magic symbol) ({G} magic symbol) ({G} magic symbol) ({W} magic symbol) ({W} magic symbol) ({U} magic symbol) ({U} magic symbol) , and perform other actions dependent on how many times the specific abilities have triggered that turn.
Repeat.
Notes
You may cast
Doppelgang for more mana each time to also create copies of other permanents. The
Mystic Sanctuary tokens can also be tapped for mana.
Results
Infinite card draw.
Near-infinite ETB.
Near-infinite LTB.
Near-infinite blue mana.
Near-infinite copies of all permanents.
Near-infinite damage.
Near-infinite death triggers.
Near-infinite green mana.
Near-infinite landfall triggers.
Near-infinite lifegain.
Near-infinite lifegain triggers.
Near-infinite magecraft triggers.
Near-infinite mana permanents you control can produce.