Double-Edged Sword is a Equip 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, Double-Edged Sword is Unlimited.
YGOPRODeck lists Double-Edged Sword for these formats: Common Charity, TCG, OCG, Master Duel.
A listed print of Double-Edged Sword appears in Amazing Defenders (AMDE-EN043) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Double-Edged Sword is about $0.05 on Cardmarket (prices change frequently).
