Rumor
Akaro didn't like this set up.
It meant that Yesfir would be with the husband more than anyone. Even if it would turn out to be a false thought, Akaro was a tsundere goddess who obviously didn't like it.
However, were the husband's knife to get this woman into it, the husband's strength would surge!
Yesfir's existence seemed like a fairy tale existence, but nothing occurred without proper explanation. At least on their level, her existence was suspicious and once charmed by the husband, she should be used by him.
The knife with this ice woman inside would be like a believer itself. She should be able to strengthen the already divine properties of it, help the husband understand the weapon, but more importantly, learn and use concepts along with it.
If the Ice Beauty's destiny was somewhere high up, then this knife might've already turned into her home.