Dual Type sentient weapon
A type of sentient weapon that as the name suggests is indeed a dual type. As there is more than one however the type part does not mean element or affinity as neither of those are unique type of sentient weapon. The dual element or affinity is something that while uncommon is not exactly rare at all. The chances of a sentient weapon having them are unlikely at least for normal typical types of sentient weapons, those being one that take a singular form. A single melee weapon, a single range weapon, or a single mid range weapon. Those are the three main forms that sentient weapons come in after all. However, the chances of having dual elements or affinities rise to be more likely in dual types. As they are not a singular weapon but instead two types of the same weapon thus the moniker dual type was given to them.