Ulrich usually uses his katana for stabbing and slashing monsters in order to destroy them. It is likely that his katana has an attack power of at least 100 LP, because he usually only needs one hit to devirtualize another member of Team Lyoko when needed. He used to have only one katana in the first three seasons, but gained another in the fourth. Ulrich also used to carry his katana in a traditional samurai sword holster until season four, in which his updated Avatar had a small backpack-esque machine on his upper back with a slot on either side. Each blade disappears into the machine as he slides them into the slots with the guard and handle still sticking out. Ulrich can also use them to block monsters' lasers and William's sword.
His katanas can also be used as long-ranged spears, by throwing them like javelins. He can also heave them into the air, causing them to spin, effectively turning them into large, sharp, flying razors. They have the ability to return to his hand after they are thrown, as long as they do not hit the ground. In the episode Franz Hopper X.A.N.A-Franz gave Ulrich access to a new Katana. It was identical to the old one, except it possessed the capability to charge up and glow with blue energy before releasing a wave that could destroy multiple enemies, much like the Energy Blade ability later used by William. This upgrade was lost when Jeremie uncovered X.A.N.A.'s ruse. Later, in the episode Nobody in Particular, Ulrich's Avatar was taken over by X.A.N.A. and his Katana was able to fire out a bluish-green, lightning-like energy blast in an attempt to destroy the Core of Lyoko. After Ulrich regained control of his body, this new power was lost.
The katana looks mostly like a real world katana. It has a light grey blade with a black guard and a pale yellow handle, mostly covered with black cloth. The blade glows light blue when it comes in contact with anything, unless X.A.N.A. has control of it, in which case the blade turns red.