Cavalier of Night | Phantasmal Image | Phyrexian Altar

Cards

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

Activate
Phyrexian Altar by sacrificing
Phantasmal Image, adding one mana of any color.
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.
Repeat.