- The 818 of this card's name represents a multiplication problem: 8 x 1 = 8.
- The number is also written in Japanese on this monster's skirt: 八壱八.
- This card is the first non-Synchro "Karakuri" monster, as well as the first TCG-original "Karakuri" monster, to be printed as an Ultra Rare in a booster pack.
- This card also has the highest ATK of any Level 4 or lower "Karakuri" monster.
- "Muso" means "Unrivaled", "Matchless", or "Peerless" in Japanese.
- This monster was based on the sohei of Feudal Japan. "Sohei" means "Warrior Monk."
- The weapon this monster is holding in its hands is a jumonji yari (cross-shaped spear), a weapon of ashigaru (footsoldiers) and samurai in Feudal Japan.