Cavalier of Night | Phantasmal Image | Altar of Dementia

Cards

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

Activate
Altar of Dementia 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
Altar of Dementia ability from step 1.
Repeat.