Sevilla is the luckiest team I saw and they didn't have good players or even a good coach this season, also in most of the games, Sevilla couldn't even have a good performance and the only reason for them to win this title was using the mistakes other teams had and they also had enough luck to win the hardest games against strongest teams like Manchester United in this season.
That's why I can blame Roma and Mourinho for anything when they lost the game against Sevilla.
In football you need some luck to achieve some certain feats and that's why Sevilla players and fans are celebrating being winners of this season's UEFA Europa League competition when it is very clear that Roma were the better side between them in the final.
However the Europa League trophy has been won already by Sevilla, so wether they were lucky or not they'll doesn't change anything in the history of the competition
Even though Sevilla don't have a very good squad overall, they are smart in taking advantage of opponents' weaknesses. And in smart football reading the game situation is very important and Sevilla can do that well. They even repeated the same strategy over and over again, they only aimed for a draw in the first leg, and in the second leg they beat their opponent at home, and it was very successful.