Visual Adjustments Mod:
https://github.com/BarleyFlour/WrathVisualAdjustmentsMod
You use it to modify the
cosmetic appearances of your companion characters, including voice barks, portrait, character doll model and their weapons and armor.
My new Seelah:
The only downside is that the voiced story dialog lines will still be in the original VA, and while you can disable voice acting it isn't per-character, so you're stuck with the original VA during dialog scenes.
Perhaps there's a way to delete only Seelah's dialog VA from the game files? I haven't bothered looking yet, maybe it is as simple as that. For new Seelah's voice barks I picked "Queen Galfrey", she sounds cute.