World Legacy Key is a Continuous 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, World Legacy Key is Unlimited.
YGOPRODeck lists World Legacy Key for these formats: TCG, OCG, Master Duel.
World Legacy Key belongs to the Mekk-Knight archetype—use that tag when searching for engine pieces and tech options.
A listed print of World Legacy Key appears in 2018 Mega-Tin Mega Pack (MP18-EN206) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for World Legacy Key is about $0.19 on TCGPlayer (prices change frequently).
