Characters / O-Parts Hunter

Jio Freed

• Animal Motifs: Wolves, since he was raised by a wolf, the markings on his cheeks & his O-Part were named after said wolf.
  • Animal-Themed Fighting Style: Having been trained by a wolf, Jio's fighting style is often compared to a wolf's movements.
• Battle Boomerang: Jio's O-Part.
• Big Eater: Seen in the first chapter.
• Bodyguard Crush: Jio declares himself Ruby's bodyguard until she pays him back for helping him, and develops feelings for her throughout the series.
• Deal with the Devil: Makes one during the fight against Wise.
• Determinator: Better demonstrated at the end of the Entotsu City Arc. Nothing can make him stop before defeating Wise Yuri.
• Enemy Within: Satan.
• Facial Markings: In honor of the Wolf who raised him. Also gains some when Satan takes over.
• Heroic Sacrifice: Performs one in the Finale with Ruby, Cross, Zero & Jack to stop Armageddon
• Mark of the Beast: When his Superpowered Evil Side takes over. also gains one on the palm of his hand by making a Deal with the Devil during the fight against Wise Yuri
• Named Weapons: Zero Shiki (like above, named after the wolf who raised him). Becomes Shin Zero later on and during the Timeskip, becomes Zero R.
• Rummage Sale Reject: Half his outfit is Black and the other half is White.
• Satan: Who is sealed inside Jio.
• Sealed Inside a Person-Shaped Can: He is this person. How he came to be this is one of the biggest mysteries of the series. In the Grand Finale, Satan himself tell him he was created to be this from the very beginning to Satan by two scientists called Adam and Eve.
• Scarf of Asskicking: Wears one pretty much by default.
• Signature Move: Encouraged to develop one by Kirin. See Tornado Move below.
• Split-Personality Takeover: Satan gives him a seal in his left hand around the Entatsu City arc, that have the ability to "absorb". However, he explains that everytime Jio uses it, part of his soul is taken away by Satan. Sooner or later, Satan is gonna take over control completely. In the Rockbird City Arc, this finally happens, but Ruby manages to stop it by sealing herself inside Jio.
• Superpowered Evil Side: Satan himself.
• Take Over the World: Oddly enough, a rare heroic example for someone with this ambition. He achieves it. Sort of. At least is what Ball says to his children.
• Tornado Move: Develops one after the Entotsu City arc.

Ruby Crescent

• Deep Sleep: A 4 year one that spans the Timeskip after her Heroic Sacrifice
• Disappeared Dad: The main reason for her journey is to find him. Too bad he turned out to be the leader of Zenom
• Heroic Sacrifice: She willingly gets absorbed by Satan to subdue him. Performs another one in the Finale with Jio, Cross, Zero & Jack to stop Armageddon.
• It Was a Gift: Her necklace, the Jade Pendant, given to her by her father. It is also a Power Nullifier to Satan.Her father was fully aware of this.
• Living Emotional Crutch: To Jio, more apparent in the RockBird Arc when she gives him a Cooldown Hug when he almost releases Satan. The Arc Villain exploit this.
• Ms. Fanservice: She wears skimpy clothing since the beginning of the series.
• Sealed Goodin A Can: She is the Angel No. 10, Sandalphon. That is how she is able to supress Satan's power when inside Jio.
• Sizeshifter: She gains the ability to do this to herself and others after the Timeskip.

Ball

• Accidental Truth: When introduced, he tried to impress people by pretending to be an OPT. It turned out he really was one.
• Happily Married: To Mei in the Distant Finale.
• The Lancer: To Jio. It's kind of surprising that he isn't also The Rival, considering this is a shonen manga.
• Magnetism Manipulation: His O-Part's power.
• Tooka Level In Badass: Begins the manga as a Small Name, Big Ego, but gains constant levels of badass along the story.

Kirin

• Badass Normal: He can kick ass despite not being an OPT.Later subverted when it's revealed he's a Cyclops.
• Cain and Abel: The Abel to Kujaku's Cain. Kujaku gets better though.
• Eccentric Mentor: To Jio and Ball.
• Extra Eyes: Due to his Cyclops heritage
• Good Scars, Evil Scars: Has one on his left eye so he could be more like his brother when Kujaku began to envy him.
• Magical Eye: That lets him program movements into any inanimate object within his range of sight, including projectiles and weapons.
• Master Swordsman: He's so good that he can split a boulder with a fishing rod.
• Trademark Favorite Food: Pickles. One of his hobbies is even pickling vegetables.

Cross Biancina

• Beam Spam: A technique Cross can use when in his Metatron form involves 365, 000 of them!!!
• Blow You Away: The power of his Middle Finger Ring.
• Cynicism Catalyst: His sister Lily was killed by Satan, so he set out for revenge. He got better after his fight with Jio.

• Doppelgänger Attack: Uses one against Jio where 4 clones appear and all 5 bodies each use one of his 5 O-Part powers.
• Dude Looks Like a Lady: After the Timeskip. Mei even feels his chest to see if he's a dude when she meets him.
• Heel–Face Turn: After the Timeskip, he's good friends with the main characters and left Stea.
• Heroic Sacrifice: Performs one in the Finale with Jio, Ruby, Zero & Jack to stop Armageddon.
• Knight Templar: A little too obsessed with his duties, product of his Dark and Troubled Past.
• Making a Splash / Shock and Awe: The power of his Index Finger Ring.
• Power Gives You Wings: When using Metatron's power at least.
• Religious Bruiser: A faithful worshipper of God, and he can take out 2 Men with an A-Ranked O-Part without struggle (as a kid no less).
• Sealed Good in a Can: The host of the Angel, Metatron.
• Stuff Blowing Up: The power of his Little Finger Ring.

Zero

• All of the Other Reindeer: Was ostracized by the other wolves due to his OPT status.
• Cast from Hit Points: Using his Super-Speed brings pain to his body.
• Delayed Reaction: sort of weaponises it with the ability to create sacrificial wolves that take the appearance of allies and take attacks from enemies. They still feel the pain from it though.
• Heroic Sacrifice: Performs one in the Finale with Jio, Ruby, Cross & Jack to stop Armageddon.
• Sealed Good in a Can: Host of the Angel: Zadkiel.
• Super-Speed: The power of his Bones/O-Parts. He doesn't use it much though (see Cast from Hit Points above)
• Talking Animal: Justified due to being the host of an Angel.

Mei

• Big Brother Worship: She had this to Tsubame before he disappeared. She still cares about him even after finding out he's a member of Stea and fighting him.
• Blush Sticker
• Happily Married: To Ball in the Distant Finale.
• Imaginary Love Triangle: Saw every girl that talked to Jio as a love rival (and Cross), at least before teaming up with Ball to fight her brother.
• Mind over Matter: She gains this ability when she opens her Third Eye. It can't affect living organisms though.
• Replacement Goldfish: Used Jio as one for her brother, Tsubame, who was presumed dead.
• Ship Tease: With Ball starting from during their fight with Tsubame.
• Third Eye: Due to being a Cyclops. Finally opens it during her fight with Tsubame