Cavalier of Night | Phantasmal Image | Yahenni, Undying Partisan

Cards

All permanents on the battlefield (
Phantasmal Image as a copy of
Cavalier of Night).

Activate
Yahenni by sacrificing
Phantasmal Image.
When
Phantasmal Image dies, its last ability from
Cavalier of Night triggers, returning itself from your graveyard to the battlefield as a copy of
Cavalier of Night.
When
Phantasmal Image enters the battlefield, its first triggered ability from
Cavalier of Night triggers; choose not to sacrifice a creature.
Resolve the
Yahenni ability from step 1.
Repeat.