Owner's Seal is a Normal Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Owner's Seal is Unlimited.
YGOPRODeck lists Owner's Seal for these formats: OCG GOAT, Duel Links, Common Charity, Edison, Speed Duel, TCG, OCG, Master Duel.
A listed print of Owner's Seal appears in Light of Destruction (LODT-EN094) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Owner's Seal is about $0.09 on Cardmarket (prices change frequently).
