Changing campaign stats of levelled-up characters

[Grail Quest]

I can change the starting stats of the playable characters in the official campaign, if you start playing the character when they first appear in the campaign (e.g., Isabel starting from Mission 1).

I can't seem to change the stats for levelled-up characters, though, like Godric in Haven Mission 5. Does anyone know how to do this?

[Grail Quest]

Figured out Godric. Still working on Shadya.