With the new set Throne of eldraine we get the mechanic Adventure. As i understand it, if a spell is played for its advenure it will be the adventure's type on the stack.
Possibility storm states the card that gets played has to "share a type"
1) Which card gets played?
2)If the card has adventure does the creature or adventure get played
3) what happens if I cast Merchant of the Vale as a creature instead?
Edit: added instant to cards on library and changed wording of 3rd question from played to cast
As an example: With the card Possibility Storm is on the field I play "Haggle" from the card Merchant of the Vale and the top five cards of my library (in order of how they are revealed) are Mountain, Embereth Shieldbreaker, Rimrock Knight, Claim the Firstborn, and Thrill of Possibility
Possibility storm states the card that gets played has to "share a type"
1) Which card gets played?
2)If the card has adventure does the creature or adventure get played
3) what happens if I cast Merchant of the Vale as a creature instead?
Edit: added instant to cards on library and changed wording of 3rd question from played to cast