Fate/Grand Order( Android , iOS)

That's because Jeanne Alter and Saber Alter are NOT the same kind of Alter. Jeanne is actually the same as Cu Alter.

Simply put, Arturia Alter is and always has been a corruption of Arturia as she normally is, in terms of deepest and darkest inhibitions. That's why there's still that holy air to her all the time; this is basically Arturia's most secret wishes given a darker form because of the Grail.

Jeanne and Cu however are NOT the same thing. In fact, they technically don't exist normally anyway. Both of them are actually imaginative manifestations of other people, made to best fit what they really want. Jeanne Alter is not a Grail corruption of Jeanne, but rather the Grail giving life to a Jeanne d'Arc that the now-insane Gilles de Rais wished for. She is who Caster from Fate/zero wanted to bang so much and saw in Arturia all this time.

Same applies for Cu actually, except he's the "imaginary friend" of our resident whore Medb. Her obsessive love for a super macho, crazy and insanely strong Cu gave birth to the berserker we have now. So if it looks like Cu Alter is a real beast in bed, congratulations, now you know why.

I'm proud of you, dear brother~