This mission isn't retroactive, so you have to ascend a new champion, same for other affinities.

For F2P and low-paying players, it's a very huge effort to get a champion to level 60 (as has been noted in various other threads). I actually had just leveled soulbond bowyer to 60 for the rare-only dragon tournament, and now I'm stuck having to level ANOTHER spirit affinity days later just to complete this mission which should already register as being completed??? Come on, Plarium...throw us a bone, here.    

The "wrong" part is the way Plarium handles this 2 years after release, not the grind itself.

Which one can be described like "not a very huge effor" - making another 4/6* champions or changing ingame description? 

This mission isn't retroactive, so you have to ascend a new champion, same for other affinities.

For F2P and low-paying players, it's a very huge effort to get a champion to level 60 (as has been noted in various other threads). I actually had just leveled soulbond bowyer to 60 for the rare-only dragon tournament, and now I'm stuck having to level ANOTHER spirit affinity days later just to complete this mission which should already register as being completed??? Come on, Plarium...throw us a bone, here.    

It's not a "very huge effort", it's just grinding. Yes, it needs some days of farming, but I can't see what's wrong with that.