Eight of Roan's ten scythes disappeared, leaving only two, one in each of his hands. Roan truly loved these Intent Weapons. Rean's weapons were definitely impressive, far better than any other weapon he fought against that wasn't made with Intent. As for the ones made of intent, he basically only knew Elsie and Rean.
The main reason for Roan to love these Intent Weapons was the fact they weren't really physical or material. They could cut, they could block, they could do all a physical weapon do, but they were different. Thanks to that, there was no risk of Roan's Scythes blocking each other's paths!
His Death Cross skills, for example. If used with real Scythes, he would need to be careful to make his movements without each other getting in the way. That also meant one Scythe would always move slightly earlier than the other to prevent collisions. The Intent Weapons, on the other hand, passed through each other!