Halon Oni (ハロンオニ) is a character of Bobobo-bo Bo-bobo. He is called Maloney Oni in the dub. He is the first of the Reverse Maruhage Empire's Four Heavenly Kings.
Halon Oni is a boy with a demonic tail who is a member of the Reverse Maruhage Empire, as well as part of their Four Heavenly Kings. He has an uncanny resemblance to Heppokomaru in appearance. However, he is much more sadistic in personality, and appears to be slightly shorter than Heppokomaru. Halon has a demonic tail that can vastly increase the size of his opponents. He works with a large penguin-like creature called Slim.
In his second form, Halon becomes much larger and more adult-like appearance wise. His hair has become more wild and longer, and has a small black area in it. He now wears two large shoulder pads, his devilish tail has grown longer, and now has two large devilish wings on his back! Halon also wields a very large sword as a weapon, and his speed and power have dramatically increased!
Halon Oni's main ability is "Sword Yamiken" (ソード闇拳; "Dark Fist of Swords"), which allows him to summon swords of various sizes at will. Other than that he can also fly and is a master swordsman.
Halon was first seen in the New Emperor Playoffs watching the fight between Bo-bobo and Dark Yasha. Some time later, Halon fought many other competitors, all of which he defeated by blasting a giant, but perfectly square, hole in the ground. He was then confronted by Bo-bobo's group and challenges them. When Don Patch complains about having no place to fight, Halon tries to stab him with his tail, only to have the hajike master push Heppokomaru in his way. This causes Heppokomaru's size to increase, and he is now half buried in the ground. The battle between Halon and the rebel gang takes place on him, and Halon leaves the fighting to his partner Slim. Beauty offers Halon one of their gold medals (items needed to compete in the Playoffs) if he turns Heppokomaru back to his original size, but Halon refuses it as he has already collected many more than he actually needs and reveals his status as one of the Reverse Maruhage Empire 4 Heavenly Kings. All of the sudden, Hanpen (who had been hiding in Heppokomaru's right nostril the entire time) reveals himself, excited that he has found a strong opponent. The fishcake warrior challenges Halon to a fight after making short work of Slim. Hanpen then joins forces with Bo-bobo, and the two gang up on the devilish soldier.
Throughout the fight, Halon takes heavy blows from Hanpen and Bo-bobo, and is losing the fight, until Heppokomaru's collar is torn off (due to Don Patch taking it off) causing him to go into baby mode. Halon becomes confused due to Baby Heppokomaru's actions, but after seeing how much damage the infant-minded teen does to his allies, Halon decides to sit back and watch for a while. He eventually gets bored, and decides that Heppokomaru should be eliminated, and attacks him while Heppokomaru is still half buried in the ground! Luckily, Heppokomaru's allies dig him out, and the giant angrily slams Halon into a wall! Outraged and injured, Halon decides to activate his Dark Fist, and assumes a larger, more powerful form.
Halon tries to kill Don Patch first, but Hanpen takes his attack, leaving the fishcake man's head in the shape of a crab! This attack on Hanpen angers Don Patch and his anger boils over to the point where he becomes Ikarin Patch! Ikarin Patch is much too fast to be hit by any of Halon's attacks, and (to make matters worse for Halon) gains a new, more powerful form each time his anger increases! Ikarin Patch defeats Halon with an angry stream of fast punches, but right before losing consciousness, Halon prays to his god that one day, he can be just like the man he was beaten by. His prayers are answered, and a large lightning bolt strikes Halon, turning him into... a Kopatch! Halon seems content with his new form, and he is never seen again in the series.
It can be assumed that Halon stayed with the other Kopatches of the Hajikegumi gang, as he does not appear with his allies from the Reverse Empire in Shinsetsu.
- Demonic Tail Human Battlefield: Halon Oni punctures the enemy thus the enemy grows in size and becomes an obstacle in battle.
- Big Bang (ビッグ・バン, Biggu Ban): Halon Oni summons a giant sword to pierce the opponent.
- Homing (ホーミング, Homingu): Halon Oni sends multiple swords like homing missiles.
- Super Sword Shield: Halon Oni creates two big, crossed swords to defend himself
- Double Sword Shield: Halon Oni creates four big swords to defend himself. It is more effective than Super Sword Shield.
- Aircut: When fused with his Yamiken, Halon Oni can cut the air and send it towards the opponent.
- Anime appearances: 73, 74
- Manga appearances: 170-174
- Voice Actor: Quinton Flynn (normal); David Lodge (Halon Oni's Dark Fist Form)
- Seiyuu: Daisuke Sakaguchi
- While most of the Hajikegumi Kopatches are orange with blue shoes (like Don Patch), Halon's Kopatch form is blue with red shoes.