Messenger of Peace 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, Messenger of Peace is Unlimited.
YGOPRODeck lists Messenger of Peace for these formats: GOAT, OCG GOAT, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Messenger of Peace appears in Dark Beginning 1 (DB1-EN065) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Messenger of Peace is about $0.44 on TCGPlayer (prices change frequently).
