The Scenario: Despite heavy criticism, the European Super League proposed by 12 of Europe's 12 teams went ahead as planned with only the 12 original teams. However, these teams were kicked out of their respective domestic leagues and, with FIFA and UEFA approval, these leagues decided to fuse with neighboring leagues in order to promote the competitiveness, the European Super League was trying to create. The Scottish League fused into the Premier League, to form a British Super League, the Portuguese League fused into La Liga to form an Iberian Super League, and the Swiss League fused into the Serie A. Also, in order to further promote competitiveness, a few of the top AFC Leagues are being granted spots in European competitions.

I got the idea for this Career Mode after the Super League was announced, and there were talks between the Portuguese and Spanish League directors about fusing the leagues in case the Spanish Big 3 were to leave for the Super League. (And yes this is just to have a more competitive Career Mode with Benfica).

How to create: Basically you put the 12 teams from the Super League into the Australian League (Is not in Europe and it doesn't have in game international competitions), then you merge the leagues mentioned above. I slotted the teams into each division by overall (save for one exception), except in the bottom tier I selected which teams would remain in the leagues based on Domestic Prestige to make sure the most relevant teams to each country remained. (The exception mentioned above is that I put the 3 best Swiss teams in Serie A, in place of the Big 3, otherwise all Swiss teams would go to Serie B). Then, so that the Portuguese, Scottish and Swiss Leagues wouldn't be just leftover teams, I put the Saudi, Australian and Korean leagues into them respectively, since they have the same number of teams, and have no in-game international competitions. The last thing you can do, if you organized the teams the same way I did, and if you have OCD, is put the English and Italian leftover teams in the Korean League and the Portuguese, Spanish and Swiss leftover teams in the Saudi League, so there aren't teams from the same country spread out in different leagues.