Astellar of the White Forest (Quarter Century Secret Rare)

You can send 1 Spell/Trap from your hand or field to the GY; Special Summon 1 LIGHT Spellcaster Tuner from your Deck. If a Spell/Trap(s) is sent to your GY to activate a monster's effect, while this card is in your GY (except during the Damage Step): You can Special Summon this card. You can only use each effect of "Astellar of the White Forest" once per turn.