The Evil Master Beast is the "true" form of the Evil Guardian that attacked Popora's island, having gained greater powers by mimicking the Straw Hat Pirates' memories. He is the final boss One Piece: Unlimited Adventure.
True to his name, the Evil Master Beast resemble a beast. He has a humanoid figure, but possess dragon-like features, such as a long reptilian tail and animal-like hind legs. He is extremely tall, standing almost four times the size of a normal human. He has rock-grey coloured skin, long red fur growing in various places and several crystal-like spikes on his body.
The Evil Master Beast's torso is shown to have black segments on his chest and shoulder plates, with red and yellow glowing outlines. Directly under his pectorals he has a row of small spikes, and next to each shoulder he has one large pink spike. Between his upper body and his pelvis, he has a large blue orb, resembling the one used by Monkey D. Luffy in the game that connects his upper and lower body. On the edges of his body, around the orb, he has small rows of spikes in the front, and above the row on his upper body he has two blue eyes with no visible pupils, making his lower torso resemble a face.
Each of his arms is thin, yet muscular with black segments covering his muscles and has red and yellow glowing outlines. Each of his shoulders have red fur and is mostly covered in red fur with several small pink spikes, and one very large pink spike on top of them. His upper arms is partly covered in red fur with several small and one large pink spike, and he have red tufts of fur growing at his wrists. His hands have pink spikes sticking out from each of his knuckles, and his fingers have long, curved claws.
His lower body consist of his pelvis, with a long, rock-grey tail with a red, jagged spine running down it, and hind legs, similar to the legs found at various mammals. His upper legs have several tiny spikes sticking out close to the pelvis, and have red fur growing out from just above the knee caps, down to the bottom joint of his lower legs. His feet themselves have red fur growing at the ends and each have three toes with large claws.
He has also possess a rather long and muscular neck, with a beaded necklace, similar to Portgas D. Ace's, but with larger beads and a small tuft hanging from the bead in the middle, and a very smal head. The head itself has blue eyes without pupils, and is almost completely covered in red fur with yellow streaks, except from a small area in the front and has long red hair running down his back.
After his transformation, the Evil Master Beast has been consumed by rage, and thus has become more wild and savage, and seemingly acts purely on instincts, having become nothing more than a mindless beast.
With his transformation, he has also seemingly lost whatever intelligence he may have had as Evil Guardian, taking on more animal-like behaviour, such as walking on all fours and only speaking through growls and roars. The only times he talks in human lauguage is when he calls out the names of his attacks, or other simple words.
Abilities and Powers
As a result of the Evil Guardian's transformation into the Evil Master Beast, he has received a large increase in both powers and physical attributes, and has gained new abilities as well.
Although it is not shown, it is safe to assume that he possesses the same extraordinary high physical strength he had as Evil Guardian, which has only been raised to higher levels after his transformation. He has also received a massive boost in speed. Where he as Evil Guardian could only move through slow walk, he is now able to run and is even shown being able to quickly dash around the battlefield, appearing as if he is hovering above the ground.
He is also shown to have maintained his ability to manipulate and control an unknown form of energy. With his transformation, this ability has been vastly increased, allowing him to unleash energy waves and streams with much more intensity, appearing as if they were flames, and create highly potent balls of energy.
The Evil Master Beast is also shown to have gained the ability to copy the techniques from the people, the opponent have met. By analysing the memories of his opponent, he can copy any of the stronger attacks from the people his opponent has met or faced before handed, be they devil fruit powers, special skills, or even weapon arsenals. This ability is similar to the one wielded by some of his minions, the Ancient Soldiers. Whenever he succesfully executes one of these copied attacks, a symbol related to the original user of the attack, appears.
In terms of battle style, the Evil Master Beast focuses purely on power. He launches strong attacks towards the opponent, which stops him in his tracks and then proceeds to overwhelm him with extremely powerful techniques. This is also his greatest weakness, since it takes time to execute these powerful techniques and thus leaves him wide open for other attackers.
- El Thor (神の裁き（エル･トール）, Kami no Sabaki [Eru Tōru]?, literally translated as "Judgment of God"): An attack borrowed from Enel. The Evil Master Beast focuses a large cluster of electricity above his target, and then uses it to send a huge and powerful lightning bolt crashing down from the sky, deep frying said unlucky target. Thor is the Norse god of thunder. Whenever he uses this attack, Eneru’s tomue symbol appears.
- Fire fist (火拳, Hiken?, literally meaning "Fire Fist"): An attack borrowed from Portgas D. Ace. The Evil Master Beast turns his fist into flames and launches it as a column of fire at his target. This attack is so incredibly powerful that it is able to plow through several ships in one shot. Whenever he uses this attack, the Whitebeard Pirates' jolly roger appears.
- Modoku Gas Dan MH5 (猛毒ガス弾 M・H・5, Mōdoku Gasu Dan MH5?, literally meaning "Deadly Poison Gas Bomb: MH5"): An attack borrowed from Don Krieg. A bomb containing extremely potent deadly poison gas that the Evil Master Beast launches toward the opponent. It creates a very large cloud of poison upon impact, and the gas is usually fatal to those without a gas mask. As claimed by the original user, Don Krieg, it could destroy an entire village with one shot. Whenever the Evil Master Beast uses this attack, the Krieg Pirates’ jolly roger appears.
- Ground death (浸食輪廻（グラウンド・デス）, Shinshokurinne [Guraundo Desu]?, literally translated as "Cycle of Erosion"): An attack borrowed from Crocodile. The Evil Master Beast places his hand on the ground and dries up everything in the surrounding area. This does not only include the ground, but anything and everything on it including people and even buildings, all of which is transformed into sand if it has steady contact with the ground. The speed at which things dry also seemingly increases. Whenever he uses this attack, the symbol of Baroque Works appears.
- Ice age (氷河時代（アイス･エイジ）, Hyōgajidai [Aisu Eiji]?): An attack borrowed from Aokiji. The Evil Master Beast places his hand to the ground and instantly freezes an entire huge area turning it into a cold, frozen wasteland for one week. Not only does it freezes the area, but turns anything and everything in the area, including living organisms, into completely frozen statues. It is undetermined how long the targets of this version would remain frozen. Theoretically, if used near the ocean or another large area of water, he can, like Aokiji, when placing his hand in the water, instantly freeze it (along with anything in/on it) completely solid and the actual extent of the ice could stretch for miles and last for over a week. Whenever he uses this attack, the symbol of the marine appears.
- Rokuogan (六王銃, Rokuōgan?, literally meaning "Six King Gun"): An attack borrowed from Rob Lucci. This technique is the secret and ultimate attack of the Rokushiki style. The Evil Master Beast places both his fists right in front of the target and launches a devastating shock wave, which seems to have the same power as an Impact Dial or even a Reject Dial (depending on the amount of energy absorbed by the dial), and causing massive internal injuries. Whenever he uses this attack, the symbol of the World Government appears. Oddly enough as stated by Rob Lucci, one must have absolute mastery of the other six skills of rokushiki in order to use this technique, but the Evil Master Beast is not shown using any other rokushiki skill, let alone displayed any mastery.
- Flood of rage: The Evil Master Beast's special attack and the only attack not copied from another character. He lets out a large roar, the eyes on his torso starts to glows and he lets out large and intense streams of orange energy from his body, which then flows up above him. He then falls down on all fours and forms eight large balls of red and orange energy that he then launches, one by one, towards the opponent, until he runs out of balls.
After his first battle with the Straw Hat Pirates, the Evil Guardian was defeated. However, as a consequence of his defeat, the hatred and rage that were used to create him and fuel him, was releashed in a form of orange and yellow energy that swirled above the Evil Guardian. He then reabsorbed that energy in a column of light, and as a result, he transformed into the Evil Master Beast. With regained strength and increased abilities, born from rage, he resumed where he left off and began fighting the Straw Hat Pirates again.
Despite his newfound strenght and powers, however, the Evil Master Beast, was defeated once more. This time, however, his body couldn't withstand the damage it had received, and as the battle ended, he fell to the ground with a roar. The orb in his midsection then began to glow, and in a bright explosion of light and energy, his body was incinerated, and his orb instantly shattered, ending the terror of the Evil Master Beast forever.
The Evil Master Beast appeared again in One Piece Unlimited Cruise 2: Awakeing Of A Hero as a optional boss, created by the Great Tree that can be fought as one of the severals opponents in Boss Rush Mode.
- Aside from El Thor, all of the Evil Master Beast's attacks are classified as special attacks in One Piece: Unlimited Adventure.