Regarding what we from Sevilla in this season, they had this team didn't have a performance at all in La Liga but the fact about Sevilla is they are usually successful in Europa League, and Sevilla once again win the trophy while they were not stronger than most of the other teams like Roma and Manchester United.
If I'm not wrong, I think Sevilla won the title seven times, and winning this tournament for seven times is a great achievement for any team.
No doubt with Sevilla has bad perform in La Liga but success won UEFA Europe League this season and make them qualify to Champion League next season. Actually, Sevilla is not favorite team for winning Europe League because many people favored Arsenal and Manchester United are favorite teams will winning Europe League. Can't compare with domestic league performance and Europe League because Sevilla has experienced won all Europe League participants.
Its great achievement for Sevilla won 7 Europe League tittle, Sevilla won all Europe League final participants and impressive record with La Liga team when their perform in domestic league very poor.