Coredem is partners with Jake of the Battle Brawlers. His defense and attack mode is grounded and solid. He punches the ground to destroy a Gate Card. The blue lens on Coredem's chest lights up the lines on his body, which runs through his arms to the fists powering them up for massive energy punches that hit the ground and makes rocks float up in the air, then punches them again and uses them as projectiles to smash the enemy. A dimensional hole in his palms absorbs all energy from an attack. His Battle Gear is Rock Hammer. The helmet-like structure on his head closes up during battle.
Coredem and Hawktor battled Dan in episode 45 with Spectra as their temporary owner to test Dan for which Battle Gear Drago would be compatible with. Drago and Dan won and both Hawktor and Coredem were beaten. He also used a Battle Gear called Rock Hammer.
It is revealed during episode 1 that Coredem and Aranaut were still in Marucho's possession until Dan introduces him to Jake, a beginner brawler. As a gift, Marucho offers him either Aranaut or Coredem and Jake chooses Coredem over Aranaut as his Guardian Bakugan. However, as Coredem was a Cloned Bakugan, he could not talk, something that disappointed Jake. In addition to Coredem, Jake also received the Battle Gear Rock Hammer. At first, Jake was a weak brawler, but then Julie Makimoto helped him out.
In episode 4, he appeared in Marucho's flashback. Later, he fought Avior twice. It lost the first battle but won the second one thanks to Jake's strategies and Rock Hammer.
In episode 9, Dan, Jake, Drago, and Coredem battled two twins under hypnosis and Coredem called Drago, "brother", they won, so they snapped the kids out of it, taking their Ziperator and Ramdol in the process.
In episode 14, he brawled against Sabator. He and Sabator were evenly matched.
In episode 15, he teamed up with Akwimos and battled Strikeflier and Avior. They were getting hammered until Akwimos used an ability, which froze them both inside of ice crystals, to make the battle end without an outcome.
In episode 28, he was brainwashed by Kazarina and later on he battled against Lumino Dragonoid under the hypnosis of Kazarina. Under her hypnosis, he became more animalistic and couldn't even speak, just making grunts and noises. He lost the first round but in the second round, he was winning thanks to the Advanced Fusion Ability that Kazarina gave Jake until Hawktor came in and helped Drago beat him.
In episode 33, he battled Akwimos, but in the end, it was a tie.
In episode 35, he and Jake broke free of Kazarina's hypnosis and he smashed his way through the tube where Drago was being held.
In episode 36 he fought against Lythirus, Lumagrowl, Strikeflier, and Krakix alongside Blitz Dragonoid, Dragonoid Colossus, Akwimos, Hawktor, Linehalt, and Aranaut before heading back to Neathia.
In Destiny Revealed, he was revived by Linehalt's "Forbidden Power". He is later saying goodbye to Jake while trying to get Jake to stop crying so hard.
- Ability Cards
- Phantom Blow: Adds 400 Gs to Coredem.
- Scale Arrow: Subtracts 300 Gs from the opponent.
- Core Knuckle: Adds 300 Gs to Coredem.
- Dimension Fall (Dimension Vortex): Nullifies the opponent's ability.
- Armored Exia: Absorbs the opponent's ability.
- Plate Shield: Nullifies the opponent's ability.
- Sling Exia: Subtracts 500 Gs from each opponent.
- Hammer Blow: Transfers 300 Gs from the opponent to Coredem.
- Crush Arrow (Rock Arrow): Transfers 400 Gs from the opponent to Coredem.
- Change Exia: Reflects the Gate Card's effect back to his opponent.
- Rippling Stream (Japanese version: Rolling Stream): Subtracts 400 Gs from the opponent.
- Counter Exia:Nullifies the opponent's gate card.
Fusion Ability Cards
- Advanced Fusion Ability: Doubles (or triples) Coredem's abilities doubles/triples the effects as well as being able to nullify the opponent's ability, with the risk of losing Coredem's life due to the ability pushing Coredem to his limits.
The Pyrus version comes in four variations, with 610 Gs in BakuTin/BakuTriad, 730 Gs Translucent in BakuSpin, 720 Gs BakuBoost and 630 Gs in Game Packs. The Subterra version comes in eight variations, with 640 and 650 Gs in BakuTriad, 680 Gs and 700 Gs Evil Twin Pack, 750 Gs Translucent in BakuSpin, 760 Gs in Combat Set, 780 Gs in BakuBoost and 740 Gs in the Character Pack. The Haos version comes in only one variation, with 610 Gs in BakuTriad. The Darkus version comes in three variations, with 760 Gs in BakuShadow, 850 in Walgreens combo packs and in a Wave 2 BakuBoost 800 Gs. The Aquos version comes in only one variation, with 740 Gs Translucent in BakuSpin. The Ventus version comes in only two variations, with 640 Gs in Game Pack and 650 Gs in BakuTriad.
In Japan, the Subterra version in GP-001 comes with 560 G.
- The helmet-like structure on his head closes up during battle, looks much like Optimus Prime from Transformers.
- Coredem's appearance in Bakugan form shares many physical traits with the 5th Paladin.
- His abilities ending with "Exia" may be a reference to GN-001 Gundam Exia of Mobile Suit Gundam 00.
- Each time Coredem is equipped with a Battle Gear, his pupils seem to disappear.
- He is the first and only Bakugan to use an Advanced Fusion Ability.
- Coredem's personality in episode 28 is similar to that of Preyas after Klaus brought him back from the Doom Dimension.