Trinity Armor/Gameplay

The Trinity Armor is a robotic Unversed first fought as a boss in the Radiant Garden, later appearing at the Mirage Arena, where players can face it again with their friends in a co-op setting or by themselves. The Trinity Armor's torso, arms, and legs are encountered separately by Terra, Ventus, and Aqua, the trio later reuniting to battle the fully assembled Trinity Armor after following each separate body part to the same location.

Kingdom Hearts Birth by Sleep
Terra exits Merlin's house to find the Trinity Armor's legs fly past him. He then follows it to an open courtyard. Meanwhile, the Unversed's torso and arms appear before Ventus and Aqua, the torso appearing before Ventus after he is stopped from entering Ansem the Wise's castle by Dilan and Aeleus, the arms appearing to Aqua after she rescues Kairi from a swarm of lesser Unversed with King Mickey's help. Ventus and Aqua follow the torso and arms to the same courtyard the legs led Terra to, the limbs and torso assembling to form the Trinity Armor. The trio unites to battle it, and they are victorious.

Design
The Trinity Armor is a large, robotic Unversed that bears a striking resemblance to the Guard Armor Heartless, as it is made up of three smaller Unversed. One resembles a small helicopter and makes up the arms. Another makes up the legs, and the last one makes up the head and torso. When combined, a black helmet will appear to complete its transformation. Both helmets have red eyes set in an angered expression.

The Trinity Armor's name references the fact that it is comprised of three main sections.

Strategy
By now, the player should have a relatively strong sense of Terra, Ventus, or Aqua's strengths and weaknesses, so knowing how and when to use a certain technique should not be an issue. Not only will the player have access to Shotlocks, D-Links, and Command Styles, but they also will have help from the two other playable characters that were not selected at the beginning of the game, who act as party members. These two other characters have a high power level and do not need to be healed. Should they faint, they will automatically revive themselves with time. As the Trinity Armor is comprised of thee separate parts, each will need to be defeated to clear the battle. Thus, having patience is a must. Depending on the playable character you chose, a different strategy will be needed for each. While the battle will be generally the same for all three characters, one must rely heavily on each character's separate strengths and weaknesses to turn the tide of the battle (Terra will excel in strength, Aqua magic, and Ventus speed).

At the start of the battle, immediately Lock-On to one of the limbs. This most likely will be the legs. Begin an immediate offense, but be sure to keep at a constant hit-and-run strategy. A majority of the battle will be spent trying to avoid the Trinity Armor's various long-range laser attacks, so this is important to do. At first, the complete Trinity Armor will attempt to bombard Terra, Ventus, and Aqua with energy balls. Several will spawn, and to top it off, the Trinity Armor will then rush at the player's character. Guard or Reflect (depending on which character chosen) can be used to avoid it. Any counter-type Deck Command can be chained to the player's blocking technique to avoid damage while still harming the boss. Continue an onslaught of attacks and dodge when necessary, and eventually the limbs that the player has Locked-On to will be destroyed, dropping much-needed HP balls as a result.

If only the arms and the torso remain, the two will have a strong chance of double-teaming the trio of Keyblade wielders to shoot a massive laser as they rotate around the battlefield. Continuously Slide, Wheel Roll, or Dodge Roll to avoid the attack, and try to stay near the edge of the battlefield at all times. When the arms are destroyed, the torso will proceed to spin wildly around the area, shooting several lasers in all directions. Again, staying near the edge of the battlefield is recommended for avoiding them as much as possible. Should the torso appear much higher off the ground than usual as it shines with a dark aura, it will proceed to fire a long-ranged laser, spinning in circles as it does so. Bombard the Trinity Armor's torso with aerial combos and magic from behind, and try to stay there until the attack has ended. So long as the player remembers the character they chose's strengths and weaknesses, uses all special abilities when possible, heals when necessarily, and most importantly, has patience, the Trinity Armor will eventually fall in defeat.

Tyrant Gathering
The Trinity Armor returns at the Mirage Arena, fought in the Tyrant Gathering round. Serving as the final boss after several waves of Unversed have been defeated, the Trinity Armor will utilize the same attacks as in its first battle with Terra, Ventus, and Aqua; 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 Trinity Armor as a different character than the one they originally beat it as in the main storyline, 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 Trinity Armor will be quite easy to defeat, clearing the Tyrant Gathering round once and for all.

Revenge of Champion
The Trinity Armor makes a last stand in the Revenge of Champion 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.