Coolest weapons in games

[Leynos]

Yamato Devil May Cry. Looks like an ordinary Katana, but it can slice reality itself. It can even divide a person into each of their individual personality traits into individual beings.

Bayonetta 2 chainsaws. You can attach them to your feet and skate on chainsaws. 

Jet Stream Sam's Muramasa in Metal Gear Rising. The blade is superheated and can cut down to the molecule. To top it off, to unsheath it, you shoot it out of the sheath like a gun.