There's the book back as well:
Xianghua's children in a familiar colour scheme:
I share some additional scans of the bonus artwork
Here are Xianghua's offspring using the parent's weapons. Aren't they cute pretending to be grown up?
I don't have the translations, but I think it's the parents cosplaying as the children
After digging around I found an even more secret version of the ultimate forms of the alexander siblings:
The caption for this one was "Oh please protect me Pyrrha I'm so scared of the big bad nightmare"
Maybe Patroklos is secretly wishing he grew up strong and courageous like Pyrrha.
Then here's the secret ultra-ultimate forms of the alexander siblings
Clearly, not patroklos's bravest moment.