A 4-1-2-3 seems most logical to me.
Covering and stopper CBs
Attacking full backs
Anchor man
Deep-lying playmaker support; Advanced playmaker attack
Messi as a poacher in the center with a deep-lying forward (support) on either side
Obviously, play around with the PIs to suit the players. I would suggest modifying the DLFs so they take long shots rarely and run with the ball often, and make sure your attacking FBs are closing down the entire field, set to man-marking, and are tackling hard.
Villa and Sanchez will be making runs from deeper and supplying Messi, who will stay at the edge of the defense and score many a wonder goal. The three will work well together. You have the best anchor man, the best DLP, and the best AP in the world, so Raikan's destroyer-passer-creator formation seems logical. The attacking full backs will be another asset in the final third. You should have a five-man-wide attacking formation.
Good luck!
