An irregular exceptionality is that which we can see in this stats of Bayer Leverkusen in their las season records, it's actually a record in the history of European football, like you did mentioned, Arsenal have done something similar but it was only I. The premier league but in the case of Leverkusen they did it across almost all three leagues they participated in except for the final game they has against Atlanta where they were unable give the record a cap and seal the record to be set.

I believe it's going to take a whole lot of years from now before any team in Europe will be able bro rise to this point where they will be able to win their domestic league with Ann unbeaten record and then proceed further to win another league outside their domestic league with an unbeaten record in the same season, I don't know if any ream have been able to be invincible in the champions league, I mean that will be one of the biggest but I don't know if it has been done before now in previous seasons. Madrid did attempted something similar last season in their domestic league (La Liga ) but they suffered one loss and also suffered another in the champions league too.

I will be most amazed to see Leverkusen get to do or repeat similar result again probably next season or in the future but it will be really superb if it happens almost immediately again but the possibility of such is very close to impossible because other teams around will not allow Leverkusen get to do such just like that. In the bundesliga Leverkusen's rivals this season will be much and tough and in the champions league, their rivals are going bro be teams they are unfamiliar with as they may have not played against such team before since they are not a regular appearance in the champions league.