Cast Black Lotus by paying {0}.
Activate Black Lotus by tapping and sacrificing it, adding {G}{G}{G}.
Cast Black Lotus from your graveyard for its retrace cost by discarding a land card.
Activate Black Lotus by tapping and sacrificing it, adding {G}{G}{G}.
Cast Invasion of Shandalar from your graveyard for its retrace cost by paying {3}{G}{G} and discarding a land card.
When Invasion of Shandalar triggers, it triggers, returning Black Lotus and two land cards from your graveyard to your hand.
Activate Claws of Gix by paying {1} and sacrificing Invasion of Shandalar, causing you to gain 1 life.
Repeat.

Infinite lifegain triggers

Infinite lifegain

Combos with "Invasion of Shandalar // Leyline Surge"