This all feels so familiar to me. In 2002 my local team Hannover got promoted into the Bundesliga. Was a fantastic season the year they went up, so many great memories. We had a Czech player, Jan Simak, 22 years old at the time, he completely dominated the league. Scored 18 goals as a midfield player. He was basically that team's Iliman, way too good for that league. Became a Czech international as well that season. Everybody was looking forward to watch him in the Bundesliga. And then he forced his way out, was pretty ugly. Went to Leverkusen and was never the same player.
It's a bittersweet feeling, celebrating promotion and losing your best player in the process. The team still managed to stay up though. So, there is hope.