If KitKat & Bacon would be weapons, together they'd be a pair of wind and fire wheels, (look it up) I imagine them being wielded by Runie as a meister because, idk about you, but I feel like the trio pairs well together. They wouldn't take advantage of Runie's strength as much as say, gauntlets, but his strength would allow them to do more damage with each slice as wind and fire wheels are CQC weaponry mainly used for slashing. But they could be wielded by anyone tbh, as long as that person can handle their sibling bickering.
Senienna is probably a meister, but if they were a weapon, they'd would be a bow, since they prefer long range combat and remaining agile.
Also, this has way too many edits because my brain is fried after work today an I've had so many misspellings and violations of basic grammar. I also now corrected the name of the weapon for more clarity as I knew it by a different name.
