Soul Transition 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, Soul Transition is Unlimited.
YGOPRODeck lists Soul Transition for these formats: Duel Links, TCG, OCG, Master Duel.
A listed print of Soul Transition appears in Secrets of Eternity (SECE-EN078) at Secret Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Soul Transition is about $0.01 on eBay (prices change frequently).
