Sevilla is the most successful club in the history of the UEFA Europa League competition having won the competition in seven different occasions, four more than any other club has managed to win it.
But that I don't think automatically means that they're gonna win it each time they play in the competition. They've not been performing so well in the UEFA Champions League this season and might end up playing in the UEFA Europa League again but there's every possiblity that they're not gonna make it to the finals.
It does of course never mean anything automatically. Past success is no indicator for future success although it might hold true in some circumstances when a team can be kept together and they are able to maintain a certain squad and momentum, like Real Madrid has done it in the Champions League with their 3 wins in a row.
But in about 2 weeks Sevilla has their most important game in the Champions League so far when the will play against Arsenal. They haven't lost a game yet and it will be about that one game, which then determines their position for the rest of the group stage.
Their story in the Europa League is unprecedented and I guess what they have done last season hasn't been done before, or certainly not very often. A team with so many problems in their domestic league to beat the toughest opponents in the competition, then win the competition and qualify for the Champions League despite failing in their domestic league, that is a remarkable result and also like an emergency exit for a team that screwed up their season in the league.