Your Celestial blood enables you to innately cast more magic. You learn the tongues spell and can cast it at will, without expending a spell slot and without material components. You also learn charm person and divination, each of which you can cast once without expending a spell slot. You regain the ability to cast those two spells in this way when you finish a long rest. Charisma is your spellcasting ability for all three spells.