(This is pretty funny to post since Lelouch don't even use a single weapon in Code Geass)
Primary Weapon - Sacred Blade
Weapon Description - This is a blade said to be handed down by the Archangels in the past. It is said that the blade is the key to open the six ultimate powers ever existed on the Earth. The blade can be un-arranged into 6 blade parts, which all are able to slash (Like a buster sword final form) and the blade has no special powers yet unless a special events occur to the blade itself. The blade is normally carried in 3 parts - one (2 parts) in the back, one (2 parts) holding and one (2 parts) hanging at the side of the waist.
Uses - Since the blade is like from the ones from Square-Enix, it is pretty big and even one slash can kill those so-called-deaths.
Secondary Weapon - Gun Blade
Weapon Description - This is one of the 2 combined parts of the Sacred Blade which is normally carried at the waist. It need ammo like any other guns.