Displacer Kitten | Invasion of Arcavios // Invocation of the Founders | Dark Ritual

(and one other card)

Instant / Sorcery that costs or less

Dark Ritual in hand.
Instant / Sorcery that costs ({B} magic symbol) ({B} magic symbol) or less in hand or in your graveyard or in your library.
Displacer Kitten and
Invasion of Arcavios // Invocation of the Founders on the battlefield.

Cast
Dark Ritual by paying ({B} magic symbol) .
Displacer Kitten triggers, blinking
Invasion of Arcavios.
When
Invasion of Arcavios enters the battlefield, it triggers, searching your library or graveyard for the additional instant or sorcery and putting it into your hand.
Resolve
Dark Ritual, adding ({B} magic symbol) ({B} magic symbol) ({B} magic symbol) .
Cast the additional instant or sorcery by paying at most ({B} magic symbol) ({B} magic symbol) .
Displacer Kitten triggers, blinking
Invasion of Arcavios.
When
Invasion of Arcavios enters the battlefield, it triggers, returning
Dark Ritual from your graveyard to your hand.
Resolve the additional instant or sorcery.
Repeat.

Infinite storm count.
Infinite magecraft triggers.
Infinite black mana.
Infinite casts of the other instant or sorcery with mana cost equal to or less than ({B} magic symbol) ({B} magic symbol) .