Araumi of the Dead Tide and Mesmeric Orb on the battlefield.
Araumi does not have summoning sickness.
You have at least two opponents.
You have at least one additional card in your graveyard for each opponent you have.
({2} 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 Kelpie Guide encore until end of turn.
Activate Kelpie Guide's encore ability by paying ({2} 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 Kelpie Guide's first ability by tapping it, untapping a different Kelpie Guide.
Mesmeric Orb triggers, causing you to mill a card.