Boss Rush 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, Boss Rush is Unlimited.
YGOPRODeck lists Boss Rush for these formats: Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
Boss Rush belongs to the B.E.S. archetype—use that tag when searching for engine pieces and tech options.
A listed print of Boss Rush appears in Dark Revelation Volume 4 (DR04-EN107) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Boss Rush is about $0.10 on Cardmarket (prices change frequently).
