You can only use each effect of "Constellar Sombre" once per turn. While this card is in the Graveyard, if it was sent there this turn, you can Normal Summon 1 "Constellar" monster for 1 less Tribute.
You can banish 1 "Constellar" monster from your Graveyard, then target 1 "Constellar" monster in your Graveyard; add that target to your hand, also, this card gains the following effect.
?This turn: You can activate this effect; Normal Summon 1 "Constellar" monster.