The Wheel Master is a large Unversed resembling a spinning wheel. Its main body is comprised of a long, red column with its black head placed near the top. The tip of the column has three silver spikes on it, and its left side is lined by a few spikes as well. A long, bent, red arm with black joint connects a large, black wheel to the top of the column. This wheel has five red spokes in it and five white spikes on its outer edge. A similar, but shorter arm is attached to the main column just below the Wheel Master’s head, and ends in a large, black, claw-like spool with gold wire wrapped around it. A wide, flat, brown protrusion attaches to the main column just above the base and connects to two of the Unversed's legs. Its third leg is connected to the base of the column on the opposite side as the other two. Its red eyes are set in a sorrowful expression and the Unversed insignia is displayed on the base of the column.
In Kingdom Hearts Birth by Sleep Final Mix, the Wheel Master receives a recoloration. The red sections of its body become white with gold highlights, its black joints become a dark blue color, and all of the silver spikes on its body switch to han blue. The board-like protrusion that connects its legs changed from brown to a faded red color, the claws on its spool become silver, and the wire on the spool becomes green.
 Kingdom Hearts Birth by Sleep
Maleficent, temporarily controlling the darkness within Terra's heart, causes the Keyblade wielder to steal a sleeping Princess Aurora's heart. Maleficent then attempts to recruit Terra to her side by offering him information about Master Xehanort, but Terra refuses. His and Maleficent's discussion is interrupted by a tremor that erupts throughout the castle. Maleficent declaring the Unversed wish to disturb them before she finally vanishes, Terra runs down to the throne room to face the Wheel Master.
As the one of the first bosses fought the game, the Wheel Master will test the player's knowledge of the controls of the game, as well as Terra's fighting style, strengths, and weaknesses. Terra will have access to D-Links, Command Styles, and Shotlocks, so the player should use these special abilities to their advantage. It is also important that the player use a constant hit-and-run strategy.
At the start of the battle, the Wheel Master will fire a beam of energy from its spindle-like arm at Terra. If it hits, the player will need to rapidly tap to escape. Otherwise, this attack can be safely defended against with a well-timed Guard. One can also target the spindle-like arm with Lock-On and deplete its HP to prevent the beam attack from being used again at any point in the battle. This is not necessary to defeat the Wheel Master, however. If the Unversed boss leaps high into the air, either Slide out of the way or jump. Failure to dodge this attack will cause Terra to take damage from the short-ranged shockwave that results from the Unversed's landing. A well-timed jump may even allow the player to land a few attacks of their own on the Wheel Master before reverting to the hit-and-run strategy. It can also be beneficial to bait the Wheel Master under one of the covered arches in the corners of the room in order to impede its ability to jump, however if attacks are not dealt quickly enough, it will escape.
Another attack in the Wheel Master's arsenal is it throwing its spinning wheel-like attachment at Terra, something signified by the Unversed boss suddenly starting to spin its upper body in circles while a whirlwind surrounds it. Slide or Block can be used to evade the incoming projectile. After the execution of this attack, the boss will leave itself open to damage for a period, eventually reverting to its technique of jumping at Terra and spawning a shockwave with each landing. Eventually, these jumps will lead the Wheel Master to the location of its dropped appendage, which it will then pick up and reattach to itself. It may also repeat the beam attack. The same strategies can be used to avoid it.
After taking enough damage, the Wheel Master will slump over, stunned, dropping much-needed HP orbs for Terra to pick up. Now is the time to bombard the Wheel Master with everything in Terra's arsenal from magic to physical combos. When the Wheel Master comes back to its senses, it will spin from side to side, dealing damage with each hit. Slide is Terra's best way of avoiding damage. For a majority of the battle afterwards, the Unversed boss will simply repeat previously seen attacks, such as the jumping shockwave attack and spinning wheel throw. Again, utilize the same strategies as earlier on to avoid these attacks. The Wheel Master will only have access to one other attack, one that is only available near the end of the battle as its last HP bar becomes visible. During this tactic's execution, the Wheel Master will shine with energy, charging at Terra. Slide is recommended for use in order to stay ahead of the boss. Long range magic commands make this battle much simpler, so make sure to make good use of commands like fire and blizzard. So long as the player heals when necessary and utilizes all special abilities when available, the Wheel Master will fall in due time.
 Rematches at the Mirage Arena
 Weaver Fever
The Wheel Master returns at the Mirage Arena, fought in the Weaver Fever round, one named specifically for it. Serving as the final boss after three waves of Unversed have been defeated, the Wheel Master will utilize the same attacks as in its first battle with Terra; the same strategies can be utilized to defeat it this time. The only differences in this battle will be the Unversed boss's greatly increased HP amount, the possible presence of any friends if the player selects co-op mode, and the increased power of the player's attacks. Should the player choose to face the Wheel Master as Aqua or Ventus, they merely must change strategies to one that suits a particular character's strengths and weaknesses (recall that Terra favors brute strength, Aqua her magic, and Ventus speed). Due to the player's greatly increased power and any help the player may get from friends, the Wheel Master will be quite easy to defeat, clearing the Weaver Fever round once and for all.
The Wheel Master makes a last stand in the Villains' Vendetta round. The same strategies utilized in past battles can be used to defeat it this time. The player should make sure that their character is at a relatively high level, having his or her most powerful abilities equipped. This will not only ensure that maximum damage is dealt to boss, but also that the player's character takes as little damage as possible. As always, remember Terra, Aqua, and Ventus's different fighting styles, make full use of Command Styles and the like, and be sure to heal if necessary.