This would be awesome to pull off. I think this is mostly someone elses idea, but i liked it so I caded up this concept sketch. middle arm rotates around its base (maybe all the way around?!). 1 CIM motor imbedded in the arm can run both saw blades counter to each other. O-all dimensions: 17wx24lx6h, when arm is in position above. The motors are expensive off robot marketplace: $155 each, NPC-41250.

advantages: rotating arm allows for greater attack possibilities. Also might be able to pull of climbing in and out of the arena with it. Doubles as flipping mechanism if we want to remove some stuff to add defensive things (who knows if this is possible).