Unstable Evolution 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, Unstable Evolution is Unlimited.
YGOPRODeck lists Unstable Evolution for these formats: Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Unstable Evolution appears in Battle Pack 3: Monster League (BP03-EN157) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Unstable Evolution is about $0.07 on Cardmarket (prices change frequently).
