She loved the Kathresis - as she loved the Bezorel. She loved it enough to internalize its weaknesses, which were vast. 

She felt pity, the pity of a god burning through the heart of the Aeteline. Akaithon, darling - you chased her shadow still. Just like you threw aside your lance to take up her discarded greatsword, now you threw aside your God to live inside her cast-off cocoon. Much of Kathresis' power had come from the fact that it was unexpected, and now it was being wielded against the only person who knew exactly what to expect from it.

The problem with a machine like the Kathresis was that if everything worked out you looked like a genius. If things went even slightly wrong you looked like a fool. 

She has changed the Aeteline not at all. She walks into the arena with the vicious aura of normality hanging over her. Where was the trick? Where was the blade? Where was the heart?

She showed nothing. Her stance gave no information, hesitation or weakness. She was the mountain and it was Akai's to walk her. Climb if you can.