The Leviathan has a black handle with an elegant, curved, light blue guard. The two halves of the guard do not connect to the top of the handle, similar to the Rainfell. The shaft is blue and it has slightly concave edges. The head and teeth are comprised of a large, circular hook that nearly forms a complete circle. This hook is divided into alternating, black and blue segments, and its outer edge is lined by spikes. The Keychain token resembles a completely blue version of the head of the blade. Overall, the shape vaguely resembles the "Final Fantasy" summon.
The name and the shape are a reference to the eponymous water-elemental Summon in the Final Fantasy series. Similarly, by equipping Nimble Gear, Axel can wield the Ifrit, also named after a Final Fantasy Summon.
During Kingdom Hearts 358/2 Days's development, this Keyblade was to take an aerial attack-oriented form known as the "Wind Maker" (ウィンドメイカー, Windo Meikā?) when the Wing Gear (ウィングギア, Wingu Gia?) was equipped. Both the Keyblade and Gear were ultimately cut and the Wind Maker's appearance given to Leviathan.
The basic ground combo contains a total of 4 attacks, with 2 separate options for the last attack. The first attack is a dashing backflip slash that is then followed by a forward thrust. The third attack is another quick backflip slash (in place), and the standard fourth attack is a horizontal slash. The option for the alternate combo arises after the third attack and is initiated with ; Roxas/Xion will perform a spinning frontflip attack that ends in a strong downward slash. The slash spikes the enemy downward, but since the attack is barely above the ground, the effect is minimized. Having a Block panel equipped with the ability Combo-Block active may make it more difficult to use the alternate 4th attack, as also executes the Guard ability. If this is the case, one must make sure to have the directional pad pressed (in any direction) to use the combo.
The basic aerial combo consists of five separate phases.
The complete aerial combo of this weapon nets Roxas or Xion a lot of horizontal distance, allowing them to reach some locations (and chests) at the beginning of the game otherwise unreachable without high leveled Air Slides or High Jumps. A prime example is in the central area of Agrabah; one can use the combos to travel amongst the high ledges. Abyssal Tide's aerial combo is highly similar and slightly inferior at doing this.