The Brazilian midfielder, 26, was expected to join Manuel Pellegrini's side in January but they ran out of time to complete the deal before the transfer deadline, meaning they had to wait until now to complete the deal. He joins Yaya Toure, Fernandinho and Javi Garcia in vying for a place in the first team - something he will relish having starred for Porto in recent years.
Nicknamed 'the Octopus' back in Portugal, Fernando has drawn plaudits for breaking up opposition attacks and interception passes - a welcome addition to Pellegrini's side given how Fernandinho and Toure love to get from box to box. City have been lacking a true holding midfielder since allowing Nigel de Jong to sign for AC Milan, so its a valuable addition.
However, the completion of the deal has to make you wonder whether Arsenal should've been pursuing Fernando as well.
The Gunners have openly admitted that they have enough ball playing midfield players having turned down the opportunity to re-sign former captain Cesc Fabregas, who was eventually sold by Barcelona to Chelsea for £30m. In acknowledging that, manager Arsene Wenger is essentially suggesting that they instead need someone more defensively-minded.
In Arsenal's 4-2-3-1 system, they play with two holding midfield players - who were usually Mathieu Flamini and Mikel Arteta last season. Flamini proved to be a welcome surprise for the Gunners having returned to the club on a free transfer, but Spaniard Arteta struggled throughout the season - leading to speculation that he could be replaced.
Arsenal may have ended their nine-year trophy drought with the FA Cup final win over Hull City, but in order to keep winning silverware, they need to add more grit and fight to their midfield. Flamini provided some of that, but they need someone who can offer more in other aspects of the game - which is what Fernando could've offered.
For just £12m, it's unlikely that Arsenal will be able to find someone of Fernando's quality at that price. Of course, City's wealth could've played a huge part if the Gunners did try to go toe-to-toe with the Premier League champions, but it's concerning that Fernando moved to the Etihad Stadium without so much as a whisper of interest from Arsenal.