Basically, he's evil. Though he can be seen as nice to his son, and he deeply cares for Lloyd, he is normally shown as being his usual evil self. He has gone to many lengths to obtain the Four Golden Weapons, and therefore some could say he is obsessed with them (which he sort of is). He also hates many people, especially Kai. In episode 9: The Green Ninja, when Kai accuses him of trying to steal the Golden Weapons, Garmadon replies: "You need to be taught a lesson boy." Despite being evil Garmadon genuienly cares for Lloyd and wants him to find his own destiny. He also seems to care for Lloyd's mother Misako.
AppearanceEditHe is seen with a metal helmet with a bone at the top, a skeleton pattern shirt underneath body armor, black pants, and known to use various weapons. In season two, he has four arms which he obtained in an unknown realm. As seen in episode 9: The Green Ninja, he was shown in a purple robe with his usual shirt and pants attire, and his hair is shown spiky and black. As a young boy, Garmadon was shown wearing white clothing and having brown hair and yellow skin, rather than his jet black skin tone he has currently. This is due to past events stated in the Story section. Before being cast into the underworld Garmadon's skin was like everyone else's except more pale and he had brown hair and wore and black and blue kimono. When being posessed by The Overlord Garmadon takes on a form resembling a crocodile. After being purged of The Overlord's evil and The Great Devourer's venom his look becomes more normal gaining white har and and black and white kimono.
As a young boy, Garmadon had a pure heart. During a training session with Wu, his brother's katana had been flung past the monestary walls. He told Wu, "Do not put off what can be done today." When Wu did not go to retrieve the sword, Garmadon had went to get it, knowing his dad would be mad if he didn't. When he bent down to get it, a venomous snake bit him, turning his heart pure evil. It is later revealed that this snake was the Great Devourer. Then, in season one, it is shown that he had made an alliance with Samukai, the king of the Skeleton Army. Having them collecting the Golden Weapons while he waited in the Underworld, he used Nya as bait for Kai when all the Weapons had been found by the Ninja. Using some type of evil power, he cast a shadow that could attack Kai and that could not be attacked by physical means. He had to withdraw when Wu entered the Fire Temple and used his shadow on the wall to appear to hit Garmadon's shadow, which in turn actually hurt him. Then in the Underworld, he betrayed Samukai. When Samukai had all the Golden Weapons the Weapons opened a portal to another realm. This could be inferred as the realm where he is seen in during episode 8: Once Bitten, Twice Shy. There Wu appeared to retrieve Garmadon, but Garmadon didn't listen to Wu and summoned Mud monsters to destroy him. When Wu told him that he came because Lloyd was in trouble, Garmadon pulled him out. Upon learning that Lloyd had released the Serpentine probably because he wanted to be like his father, Garmadon told Wu that he had never wanted Lloyd to become evil. The two traveled to the Mountain of Madness, and after fighting off monsters, they went into another portal which lead back to Ninjago. In episode 10: The Green Ninja, Garmadon temporarily makes a truce with the Ninja until they stop the Serpentine and save Lloyd. He also torments Kai with his constantly mocking expression, plus he brushes his teeth with a knife, changes the channel on the group, eats "condensed evil", and messes with lightning. All in order to mess with everybody's heads. When he goes to get the Golden Weapons for Wu, Kai comes in accusing him of stealing. He and Kai get a rematch, where he lets Kai win. When they enter the Fire Temple to stop Pythor and save Lloyd, he takes out a bunch of Serpentine in order to get to Lloyd before the Serpentine are able to escape. Once reunited with his son, they go to where the exit is. When Lloyd falls down into the magma (on a chunk of rock) and Wu tells everyone that they needed to evacuate, he protests that Lloyd was still in there and that they couldn't just leave him. At the end of the episode, he is shocked and saddened to know that Lloyd is the Green Ninja. In episode 11: All is Nothing, he tries to steal from the Ninjas' ship. When Lloyd accuses him of this and going behind his friends' backs, Garmadon explains that he can't help it since he was bitten. Lloyd continues to say that he had been left alone for so long and asked why his dad had left. To this, Garmadon replied, "There are places in this world void of any good. You know that I've always wanted those Golden Weapons. Well, this place allowed me to do so." Lloyd then asks why he didn't take him along. Garmadon told him that he had a choice whether to be bad or good, but that he never had that choice. That "evil runs through my veins", and that Lloyd should follow his destiny. Then Lloyd kicks him out and Garmadon leaves. Probably knowing that Lloyd would go to save the others, Garmadon (this was all off camera, but it is shown that this happened) went to the Underworld to ask for Samukai's help. Samukai probably said no, but when Garmadon explained about the Serpentine trying to awaken the Great Devourer, he agreed to have his Skeleton Army fight for Garmadon. (Back on the show) Garmadon arrived after Pythor asked Lloyd "You and what army?" to which Garmadon replied "How about this army?". Then he helped the Ninja get the Fang Blades. When it was time for him to leave, he vanished before Lloyd could say goodbye, but he did tell him that he was proud of his son.