At one point, Morok was going to be killed by a shadowy being which was attempting to consume him, but Leviathan saved him from death. However, Leviathan became bad at one point in his life. He got a race of tanks and turned them into slaves. Leviathan told them to work on a secret project. After the project was completed, Leviathan was originally going to get rid of them, but he realized that he could use them to expand his army. At one point, Leviathan was betrayed by Ram and Mons. He imprisoned Ram in his Labyrinth of Death and Mons in his world
38t called upon Leviathan to help him defeat The Soviets, but it was defeated by The Soviet Ratte, KV-6, The Soviet Army, and a Franken and Stein. Another time Leviathan helped the Germans during the first battle with Robo-Stalin, but it was defeated when it was hit by a golden shell, lowering its resistances and allowing Robo stalin to pull it toward him and let Leviathan destroyed by Dora's shot
Later, in the moon-base, 38t and Leichttraktor called upon Leviathan. He demands an army, but 38t tells him that they don't have the resources needed. Leviathan sends his minions to gather the resources. After his minions fail to defeat KV-44, The Artillery Monster, and Robo-Stalin, he sends them to take over the iron mines. After his minions fail to defend the iron mines, he kills Waffentrager and sends Ratte to The Labyrinth of death. He then attacks The Chinese Bunker and forces The Soviets out, turning KV-54 into his minion in the process.
Later on, Ratte escapes The Labyrinth of Death and tries to fight Leviathan. He initially wins, but Leviathan steals the power of the ones he defeated and transforms into his current form.
Then he tried to open the gate in the fortress which Morok and his army protects from Leviathan's second assault, which is his mortar The Destroyer of Gates. But Morok tries to stop Leviathan, however Power level of Morok is 26/10 but Leviathan won in that battle and Morok escapes with his army and go in their survival spot. Then Leviathan enters the throne room of his father, but his father's powers are almost as powerful as Leviathan's powers. He used his strongest shot just to remove his father's helmet, revealing his father's true face of a Demon. His father refuses to leave, but Leviathan forces his father to fight him. The father's powers are Lightning, Stalagmites and Stalagtites Magical Chains and his Tank Destroyer Gorce Feild.Then Leviathan gets stabbed by the stalagmites and passes out, but breaks them and uses his powerful shot to kill the demon and the crown fell.
After the fight with his father, he realized one part of the crown was missing so he was outraged and chased Morok with his group. He was close but failed to capture them. He then went into the moon base which is where he commanded the 38t to launch an attack against the Soviets. Leviathan was growing weaker, and dies from the 38T overthrowing him, trapping him with his machines and the modified Waffentrager Auf E100. When Leviathan died, the 38T didn't even expect every Gladiator soul from him now scatter everywhere in his base and eventually fight for themselves. Meanwhile the 38T himself, has an idea about using them. But Mimic becomes 38t and come into Leviathan body and then real 38t comes but Waffentrager auf E 100 was not able to recognize who is real but after the secret command Waffentrager fire at Mimic. Then Mimic merge with Leviathan and starts attacking but 38t blasts the tnt causing Leviathan (Mimic) to fall then he battles with Ram but Toxicus Rubbish monster and Freezer came the Mimic says that he's Leviathan but Rubbish monster was smart enough to know he's Mimic but Freezer then shoots Rubbish Monster and Toxicus then they engaged in battle and Toxicus died from Freezers ice shots and Rubbish Monster used his Harpoon and giant cannon to kill Toxicus then he battles Freezer and defeats Freezer by opening a tunnel filled with hot gas and then he battles Ram and then Ram uses a secret (or special) ability and increases in power by 11/10 (total:17/10) and defeats Rubbish and then gets all 3 abilities and then Mimic acts like Leviathan and congratulates him but Ram already knows he's not Leviathan and then they fight Ram nearly killed Mimic but Mimic feels Leviathan's memories and transforms into Mons Rams brother Ram thought it actually was his brother but then Mons (Mimic) battles him but Ram refuses to fight than Mimic uses teleportation in advantage and kills Ram
another meanwhile in the base and KV-6's brothers come to the lunar base to take the Demon King's crown, but Mimic finds them and then Executioner comes and Mimic tells him to kill them, but Executioner knew he wasn't Leviathan so he battled him and after Mimic destroys Executioner's shield he finds out he killed Faceless and Executioner uses a final move with Faceless' cannon on his mouth but Mimic swaps their place and Executioner kills his own self but then he shows his true identity of him actually killing a lot more tanks then Faceless but Mimic still wins
After some time, Leviathan was revived and killed Morok using "the sink to death". Leviathan then recruited KV6 and called him his "Assistant" for the time being. Once KV6's brother, Scientist, Rams, and Mons were able to teleport within the Soviet Fortress, they were able to meet with Leviathan and KV6. At first, KV6's brothers try to make him remember but KV6 rammed them with no mercy, reminding Leviathan of a moment in his life. Rams and Mons then fight them but in response, Leviathan sent KV6 to do the work because of try to test their trust, it was a close call but the two knew they have to use Black Magic. They both merged and fight KV6 once again but it still wasn't enough. Although KV6 was injured, Leviathan gave him a "prize", which was regenerating his injured body.
Power Levels of all Versions of Leviathan
Leviathan 1.0 8/10
Leviathan 2.0 : 17/10
Leviathan 3.0 : 35/10
Leviathan (Mimic) : 55/10
Leviathan 4.0 : 115/10
Powers and Abilities
-Sending tanks to the Death Maze: When he wants to punish tanks, he can send tanks to the Death Maze.
-Creating a portal: He can jump through dimensions and go far farther from where he is now.
-Charge attacks: He can strengthen his shots to make them stronger and increase damage.
-Cloning creation: It is seen that he was able to clone himself, shown to be used to help the Nazis and a clone to deal with Morok.
-Resurrection: Even after being killed by Demon Ratte, he came back to life.
-Purple Fire Throw: Blows fire.
-Flame Breath: In 2.0 form, he can blow purple colored fire from his mouth.
- Ice breath: He also breathes ice.
-Transform: He took different forms that changed his appearance and made him stronger.
-Force field: He built a dome-like shield around him to protect himself from powerful shots, but it has limits.
-Forcing of steel: This unique strength is like a force field with no boundaries. It is stronger than a normal force field and has no boundaries, not even a scratch. Also known as the Steel Wall.However Waffentrager was able to break it. (It was only used by Mimic).
-Tank creation: he Made Big Bertha from a dead Dora tank or sends them to the Maze of Death. It changes their appearance, gives them new powers or strengthens them.
-Harpoon gun/Laser turret: Can shoot harpoons from the laser turret.
Sink to death: The only time he actually used it is when he "sinked" Morok, sinks people into his mind however in new episode we see that morok is still alive.
Also shout out to u/ALEXTHECHIP, He always fixes it when I take more content spaced