Doom Guardian

The Doom Guardian (裁きの番人) is the “present” given to the Straw Hat Pirates after clearing all their given ordeals. However, because they were deemed evil by the Great Tree, it became the Doom Guardian. This is actually Gaburi transformed, sent as a guardian of the Great Tree to attack the Straw Hat Pirates against his will. He is the final boss of One Piece Unlimited Cruise 1: The Treasure Beneath The Waves and second-to-final boss of One Piece Unlimited Cruise 2: Awakening Of A Hero.

Appearance
He is the final boss in the One Piece: Unlimited Cruise. He has two forms. The first form resembles the first form from Unlimited Adventure final boss. The second form appears after the first form is defeated, in Episode 2. The second form resembles a spider as it begins the second part of the battle against Yami and is very tall, muscular, brown, and purple. His level in the tier list in versus mode is level 5, however, he isn't playable in survival mode.

Abilities and Powers
The Doom Guardian has displayed an immense amount of physical strength, enabling it to effortlessly lift people and throw them hard into the ground, wield its large war hammer with ease and cause massive damage when it attacks. It has also displayed impressive feats of speed for its size, being able to performing slow, but steady dashes, which allows it to reach higher levels of speed and catch up with escaping opponents.

Much like the Evil Guardian, the Doom Guardian can create and manipulate an unknown form of purple energy. This makes the Doom Guardian capable of applying destructive energies to its basic attacks, unleash shockwaves and amplify its own strength, signified by a dark aura. This also allows it to perform several energy attacks, such as creating several small orbs of energy that will home onto the opponent, launch columns of energy from the ground, from any position, fire energy beams and form large explosions.

It has also demonstrated the ability to call out his weapon from thin air itself. It is currently unknown how it does it, or it is just a game gimmick.

It’s most terrifying power is its ability to restore itself to perfect health after being defeated, despite any injuries. This allows the Doom Guardian to come back from any defeat, and continue fighting for unlimited amounts of time.

In battle, the Doom Gaurdian focuses on hindering the opponents' movements by launching attacks that stops them in their tracks or throws them off course, and then launch strong attacks against them while they are disabled.

Should the Doom Guardian face someone that is too powerful to handle in its current body, it is capable of adapting to the opponent’s strength by reanalyzing the data on the opponent and evolve into a new form, similar to that of a metamorphosis. In this new body it can better handle the opponent’s attacks, has increase powers and a new set of techniques as well.

Weapons
The Doom Guardian fights using a large war hammer, about as tall as the Doom Guardian himself. The head is rather large and made of stone, with several blue and red veins connecting it to the hilt. The hilt is purple, with a golden joint between the head and the hilt and has golden orbs on the other end. So far, the Doom Guardian is only shown using it in a rather basic manner, merely “hammering” the opponents when they get too close.

It has also displayed using it in conjunction with its energy manipulation, mainly using it to launch energy columns from the ground.

Attacks

 * Hammer of Doom: The Doom Guardian lifts up its war hammer, and hammers down the unfortunate target with great force, unleashing a purple shockwave. If it charges up before attacking, the Doom Guardian can follow the strike up with a column of energy, erupting from the ground that can hit the opponent no matter where they are. This gives the Doom Guardian a second chance at attacking the opponent, should the opponent dodge the first strike.
 * Light Spear of Destruction: The Doom Guardian points its left shoulder at the target and fires an intense and deadly purple energy beam from its shoulder that can hit the target from any distance.
 * Rain of Ruin: The Doom Guardian jumps into the air and releases several small orbs of purple energy from its left shoulder. These orbs will then automatically home onto the opponent, stopping the opponent in his tracks, while causing damage.
 * Wrathful Punishment: The Doom Guardian dashes up to the opponent and grabs him with both hands. It then lifts the opponent above itself and then throws him into the ground with great force, creating a purple shockwave.
 * Ultimate Light: The Doom Guardians special attack. It begins a slow, but steady charge of energy, creating a large, black orb of energy above itself. One charged up, it releases the energy in a giant explosion, critically damaging everything caught within the explosion.

History
After the Straw Hat Pirates had cleared all the ordeals presented to them in One Piece Unlimited Cruise 1: The Treasure Beneath The Waves, they went to the Central Isle with Gaburi, to pick up the present they were promised for clearing the ordeals. Once there, The Great Tree herself asked Gaburi to come forth. She then pulls him into her central core, in order to analyze the Straw Hat Pirates’ character and then transform Gaburi into a suitable present for them.

Initially, the Great Tree deemed the Straw Hat Pirates evil because they were pirates, but Gaburi denied it. The Great Tree then began a deeper analyze of Gaburi’s memories and she sees Gaburi’s memory of the duplicate of Blackbeard, created by the ordeals. Seeing the evil nature of humans, she became afraid and as an act of defense, she transformed Gaburi into the Doom Guardian, and forced him to attack the Straw Hat Pirates, as she returned him from her core.

Seeing that the Doom Guardian held the original part of Gaburi captive, Luffy and the others decided to defeat the Doom Guardian and free Gaburi. After a long battle, it seemed like the Straw Hat Pirates beat the Doom Guardian, but soon after it restores itself and resumes the fight. After beating the Doom Guardian a second time, the Straw Hat Pirates pulls Gaburi out from it, while it was briefly knocked out. However, by losing Gaburi, who is a part of it, the Doom Guardian goes out of control and nearly kills the Straw Hat Pirates with his Light Spear of Destruction. However, in an act of self-sacrifice, Gaburi saves them, by blocking the beam, and in an explosion of light, he forces the Doom Guardian to retreat.

Despite disappearing from plain sight, the Doom Guardian continued to exist inside the Great Tree, and was planned to be released from it, by releasing a big seed containing it. However, because of their separation, it was only a matter of time, before Gaburi and the Doom Guardian would disappear. Not allowing Gaburi to disappear, the Straw Hat Pirates began clearing the ordeals on new islands, in order to make Gaburi stronger so he could remerge with the Doom Guardian, without being taken over by it. In the meantime, the Doom Guardian was absorbing the isle’s power to get stronger, while the Great Tree was observing the Straw Hat Pirates.

Once they returned to the Central Isle, the Doom Guardian appeared before the Straw Hat Pirates once again. This time, the Doom Guardian was taken over by the Great Tree, and stated through it that humans were evil and therefore had to be destroyed. While the Straw Hat Pirates agreed that there were evil people in the world, they also said that there were good people too, and if she would call those people evil, they would stop her. Despite this statement, the Great Tree still unleashed the Doom Guardian at the Straw Hat Pirates, determined to eliminate them.

After a long battle, the Straw Hat Pirates seemly defeats the Doom Guardian, and it falls lifeless to the ground. This turns out to be a rouse, however. Instead, the Doom Guardian began a metamorphosis, evolving into better suited form to fight the Straw Hat Pirates, and emerges as the Demon of Doom.

Trivia

 * Both UC and UA final bosses resemble to each other, having 2 forms. In the first form, both resemble each other, like the heavy look, role in the game. In their second form, they look much more stronger, like the UA final boss resembles a beast, and Unlimited Cruise' final boss resembles a spider. In their 2nd forms they both mimic attacks from in game characters.
 * Yami`s name in Japanese means darkness, much like Blackbeard's Devil Fruit; the Yami Yami no Mi.