Sylvan Blessing is a Normal Trap Card.
Trap Cards are normally Set first and can be activated on a later turn, often in response to an action.
On the current TCG and OCG Forbidden & Limited lists tracked here, Sylvan Blessing is Unlimited.
YGOPRODeck lists Sylvan Blessing for these formats: Common Charity, TCG, OCG, Master Duel.
Sylvan Blessing belongs to the Sylvan archetype—use that tag when searching for engine pieces and tech options.
A listed print of Sylvan Blessing appears in 2014 Mega-Tin Mega Pack (MP14-EN232) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Sylvan Blessing is about $0.08 on Cardmarket (prices change frequently).
