The Scotsman's Sword was the prized and signature weapon of The Scotsman. Unlike Jack's Katana, which was a Japanese Katana and was used for fast and graceful attacks, the Scotsman's Sword was a Scottish Claymore and was used for powerful strikes that broke through defenses.
Similar to Jack's Sword, the Scotsman's Sword could cut through nearly any material without effort. Despite its size and weight, the Scotsman could easily wield it and fight at the same speed as Jack with it and even used it with only one hand (Episode XI: Jack and the Scotsman).
The sword was also magical, as it had been inscribed with ancient Celtic runes that made it nearly indestructible and increased its destructive power. The runes also allowed the owner of the sword to return as a ghost after they were killed. As a noble spirit, the Scotsman gained control of the power of righteousness.
Those properties made it one of the few weapons that were capable of matching Jack's Sword. However, when the Scotsman, as an old man, actually faced off against Aku, Aku used his Eye Beams that left the Scotsman vaporized and half of his sword was broken. Despite being partially destroyed, the runes inscribed on the blade allowed the Scotsman to return as a spirit, and the broken blade itself was carried into battle by his daughter, Flora (Episode XCVI). Flora then used it in the final battle against Aku (Episode CI).