The Dichotomy has a long, navy blue handle with a blue, spade-shaped pommel with gold edges. Its guard is black with gold edges, and is a crescent-like shape and points downward. The Dichotomy's blade is comprised of two identical halves. Each half is long and silver with gold inner edges.
The halves are rather smooth, though each has a small, semi-circular indentation in the middle of its outer edge. The two halves are connected by a shorter blade—roughly half the length of the two halves of the main blade—in between them. This shorter blade is blue with gold, ridged edges.
When Saïx enters his berserker state, the distance between the two halves of the main blade becomes greater, and the halves themselves becomes slightly longer. The central blade also becomes much longer.
The tip of the central blade gains a new, pale yellow blade with yellow edges lining its upper edge. The halves of the main blade each gain similar blades lining their outer edges. These blades also sport eight short spikes near the upper half of the weapon, creating a silhouette reminiscent of the Lunatic claymore.
Dichotomy is the phase of the moon where half of it appears visible, possibly a reference to how Saïx is both calm and berserk. "Crocea Mors" is Latin for "yellow death" and is the name of Julius Caesar's sword, according to the writings of Geoffrey of Monmouth.
Dichotomy's ground combo starts with a downward diagonal slash followed by an upward diagonal slash. The next move of the combo consists of Saïx performing a leaping upward diagonal slash. The combo then ends with a dash forward in mid-air, followed by a 360-degree spinning slash.
| New Moon | Werewolf | Artemis | Luminary | Selene | Moonrise | Astrologia | Crater | Lunar Phase | Crescent | Gibbous | Berserker | Twilight|
Queen of the Night | Balsamic Moon | Orbit | Light Year | King of the Night | Moonset | Horoscope | Dichotomy | Lunatic | Just Desserts | Bunnymoon
| Infinity | Final Weapon | Dragonreign | Aegis | Cardinal Virtue | Radical Treatise | Dichotomy | Prominence | Sanctuary | The Joker | Hallowed Lotus | Vol de Nuit | Omega Weapon|
Oblivion | Bond of Flame | Centurion | Frozen Pride | Star Seeker