MAGIC: THE GATHERING
Add to your mana pool.
Threshold - Add to your mana pool instead if seven or more cards are in your graveyard.
Cabal Ritual is yet another strong ritual effect used to enable the combo in Legacy Ad Nauseam Tendrils. When paired with Dark Ritual, you will never find yourself short on mana to cast Ad Nauseam, more Rituals, and an incredibly large Tendrils of Agony.