It was an imposter.
https://allthetropes.fandom.com/wiki/User_blog:Reyder_Dister/My_CM_list?diff=prev&oldid=327401
Reyder Dister has no issue with Desaix at all, while (see last entries)
https://allthetropes.org/wiki/Talk:Complete_Monster/Fire_Emblem
this Reyder Dister has. The first Reyder Dister has no issue at all with Desaix, not even calling him a "borderline case", while the other doesn't even see him as a CM at all.