You have at least one additional card in your graveyard for each opponent you have.
Mana Needed
({3} magic symbol) ({U} magic symbol) available.
Steps
Activate
Araumi by tapping it and exiling cards from your graveyard equal to the number of opponent you have, giving
Fatestitcher encore until end of turn.
Activate
Fatestitcher's encore ability by paying ({3} magic symbol) ({U} magic symbol) and exiling it, causing you to create a token copy of it with haste for each opponent you have.
Activate a
Fatestitcher by tapping it, untapping a different
Fatestitcher.
Mesmeric Orb triggers, causing you to mill a card.