Shield Crush 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, Shield Crush is Unlimited.
YGOPRODeck lists Shield Crush for these formats: OCG GOAT, Duel Links, Common Charity, Edison, Speed Duel, TCG, OCG, Master Duel.
A listed print of Shield Crush appears in Battle Pack: Epic Dawn (BP01-EN080) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Shield Crush is about $0.09 on Cardmarket (prices change frequently).
