Cleansing oneself required magic. Typically Daemos wouldn't use lakes or rivers, it was their only source of clean drinking water; doing such was seen as a transgression. Water produced by magic had no uses besides cleaning (outside of combat), so most opted for that.

Except magic was a scarcity in the human world, and Rhys insisted on conserving what little they had left. Obviously his Highness and his knights started to... well, stink. Asch didn't understand how he could possibly accomplish anything without magic.

It turns out that the human spell pool had other uses.

Of course, Asch insisted on being the only one present in this bathroom of yours. The lack of armour and protective layers put him on edge, he felt vulnerable to attack. But the human had other plans. Perhaps they still did not trust him, smart really.

He sat in the bathtub and soaked in its hot water, wondering how the human got such a large amount in such a short time. They truly are a powerful mage... He clicked his tongue, annoyed that Rhys was correct yet again. He focused on cleaning.

That required the substance humans called soap. And it was supposed to clean him, was it not? And Asch was instructed to clean every part of his body, was he not? So why was this feeble soap viciously attacking his eyes?!

"HUMAN-" Water splashed onto the tiles loudly as he struggled, "It's burning! Cease its torment at once!" Asch stumbled to his feet, covering his sore eyes. He would not be blinded so easily! He'd attack if he must.