I failed my people. I tried to protect them with all my power, but they lost their lives because of me. In the end, I became the very thing I was trying to protect them from. But I was given a second chance. I met Godzilla and the others and my faith was restored. And after meeting these humans, I've learned more than ever how important my comrades are to me. No, they're more than comrades, they're my family. As a member of Fairy Tail and as an Earth Defender, I will not fail my family. We will not fall!
-King Caesar to Gabara in "Power of Life"
King Caesar is a founding and current member of the Earth Defenders and was formerly known as the Guardian of Okinawa over a thousand years ago. During a battle against Megalon, he was put into a coma before being reawakened by Lucy Casprell to help Godzilla fight off the Trilopods.
King Caesar's appearance is inspired by a shisa, a beast resembling a combination of a lion and a dog. His snout is dinosaur-like with a mouth full of sharp teeth. His eyes are brown, but have a faint red glow in them. When he enters his berserk mode, his eyes glow completely red. His ears are normally bent like a dogs, but shoot up when aggravated.
The upper half of his body in covered in gold fur and its lower half has fur only on its legs and tail. His skin is brick-like and he has long white claws on his paws and feet. The claws on his paws grow longer and glow reddish-pink when performing Prism Claws. The top of his head has a crown-like protrusion on it with a green gem in the center.
After becoming a member of Fairy Tail, King Caesar is given a Guild Mark. His is red and is on his right shoulder.
King Caesar is normally very calm and often displays a serious personality, but is also very kind and protective of his comrades, even considering them his family. He also has a slight friendly rivalry with Rodan as the two started a bet to see which one of them could be as strong as Godzilla. He shares good relationships with his comrades, especially Manda as the two known each other in the past. During his time among the Fairy Tail mages, King Caesar seemed to developed a friendship with Gray Fullbuster, which developed further when they realized that both lost someone close them: King Caear loosing the Azumi Family and his people to Megalon and Gray loosing his his parents and his master Ur Milkovich to Deliora.
However, when he was reminded of the destruction of his home by Megalon during his battle against Gabara, he has been shown to enter a berserker-like state, in which he became much more ruthless when he battled Gabara. Not only that, he even attacked his own comrades when he envisioned Megalon in their place.
It appears that King Caesar is still haunted by the destruction of his kingdom and his battle with Megalon, these memoires being stored in his sub-conscious and being flooded through his mind in his berserk mode. He feels that he failed his people and he was partly responsible when he lost control.
Before the event with Megalon, King Caesar shared a close friendship with Princess Azumi of the Azumi Royal Family as the princess would visit him in his chamber and was actually able to speak with him.
King Caesar was artificially created by the royal Azumi family using ancient science and magic used by the first civilizations. To give life to the creature, an unidentified royal soldier who was Princess Azumi's bodyguard sacrificed his soul to be placed into a large golem, giving birth to the Kaiju. He was given his own chamber underneath the royal palace, where he would sit on huge stone throne.
At some point after his creation, he met Gabara when he attempted to attack a small village outside the Ryukyu Kingdom and defeated him in combat, knocking him off a small cliff only to disappear. He also encounter Manda at some point, while Manda was being attack by humans and so fought back, King Caesar came to stop and managed to clear up the misunderstanding and even gotten to know her.
Many years later, King Caesar is visited by Princess Azumi as they discussed earthquakes that affected neighboring kingdoms occurring in a pattern. Azumi asked if another kaiju is behind it and King Caesar says he isn't certain but stated he will defend their kingdom. Princess Azumi became worried for Caesar's safety but the guardian kaiju reassured her that he must do what he must. Azumi told him to promise her to be safe and King Caesar promises.
Later, the Ryukyu Kingdom was attacked by Megalon and King Caesar intercepted him and tried to fight him off. However, he eventually flew into a rage when he witnessed the hundreds of deaths caused by their battle and brutally fought back against Megalon near the coast. However, a Cryog ship (having been shot down by a Millennian UFO in Terra's orbit) ended up crash landing near the them and King Caesar was swallowed up in a tsunami and was supposedly killed, but some believed that he survived and was simply waiting for his chance to awaken so he could redeem himself.
Refractory Eyes: King Caesar's most noticeable ability is his ability to draw the energy beams of enemy monsters into his eyes, and fire it back at the target. He used this technique to redirect Gabara's Power Horn back at him. He was even able reflect the Loke's magic attack.
Prism Eyes: Different from his Refractory Eyes, King Caesar gathers his own energy into his eyes and fires a pinkish-red beam of energy from each of them.
Magma Eyes: A powerful version of Prism Eyes, King Caesar gathers a fiery energy in his eyes and fires a reddish orange beam of enemy from his eyes. He used this attack in his rematch against Gabara.
Prism Pulse: King Caesar can gather a large amount of energy into his hands in a sphere and tosses it at his opponents. He used this technique in his battle with Rodan in the S-Class Wizard Trials and Gabara.
Solar Beam: King Caesar has the ability to transform raw solar energy into a searing beam of lightning and fire it from his mouth. This attack was first used to defeat Gabara in their battle, blasting the conqueror off a cliff. Its stated that this attack is so powerful that it can be capable of killing an opponent.
Prism Claws: A slashing attack, the claws on King Caesar's paws can grow longer and glow a reddish-pink. King Caesar can then slash into an opponent and send them flying from the force. He used this attack in his battles against Ultear and his rematch against Gabara.
Ice-Make: Shisa's Wrath: A kaiju and human Unison Raid that King Caesar was able to perform with Gray. As the two channel their energy into their hands in unison, they fire a blast of red energy with a large ice statue of a shisa's head in the front. When the attack comes close to the target, the shisa head will open its jaws and clamp down on the opponent, followed by an explosion of red and blue energy that engulfs the target. This attack was used to defeat Gabara.
Berserker-Mode: When he was reminded by his battle with Megalon and the destruction of his Kingdom, King Caesar entered into a Berserk-Mode. In this mode, his vision sees only the destroyed Ryukyu Kingdom and anyone in his line of vision are seen as Megalon through his eyes. In this mode, his speed and strength is greatly increased. His durability is also increased as he able withstand the magic attacks of Gray, Lucy, Cana and Loke. He was even able to catch Gabara's Thunder Clobber with his paw.
Immense Strength: King Caesar possesses formidable speed, strength and agility, enabling him to perform various martial arts techniques, making him a formidable foe in close quarters combat. He is strong enough to rip Trilopods apart with his own hands. In his Berserk-mode he was strong enough to break Gabara's arm with ease and to hold Varan to ground as well as holding up Gray's Ice-Make: Hammer.
Immense Durability: Being created from a golem, King Caesar's body is rock solid and is able to horrible beatings before going down. Even his fur is thick and durable enough to be able to protect himself from projectiles and energy based attacks. He was able to physically survive a giant tsunami wave but still left him in a coma. In his Berserk-mode, he was able to withstand the magic attacks of the Fairy Tail mages.
Enhanced Speed: King Caesar is one of the fasted Kaiju on land and mostly uses his speed and impressive agility to employ his martial arts skills in combat. He was fast enough to easily outrun Battra's Prism Beams without breaking a sweat.
Enhanced Endurance: Being a master in martial arts techniques, King Caesar is able to easily conserve his energy in order for him to be able to face multiple foes without getting fatigue.