To be honest, Messi has embarked on a brilliant career at Barcelona, he has had his most wonderful moments there , joining legends like Cruyff, Maradona, Pele and Di Stefano at the top of the game..
He has won six Golden Shoes, five Ballons d'Or, etc. He has become one of the greatest at Barça and he owes Barça as much as Barça owes him.