I like how A-ko or whoever that is in the first panel is SO HYPE for toast that it cannot wait for her to put a bra on. What was that anime, Secret Wars with the guy who puts on his gun holster first even when he's still in his underwear?
I don't think a chainsaw like device would be all that effective in the size of a 1-handed sword meant to be carried by people who aren't 8-foot tall Space Marines.
My understanding is that chainsaws are not particularly useful in combat in their natural state let alone something as absurd as a double-edged chainsword. The exposed back edge is a real good way to fuck yourself up if you're not careful.