Master Core: ABIS

Master Core: ABIS (マスターコア: ABIS) is the transformation of SCR-HD, created when SCR-HD merged with Astral Babylon's artificial black hole/core unit and the energies from the five Arks of the Cosmos. It is the final (and only) boss of Sonic Riders: Zero Gravity.

After SCR-HD completed its objective of bringing the Arks of the Cosmos to Babylon Garden, it became Master Core: ABIS and tried to prevent Team Sonic and the Babylon Rogues from stopping the ship's core unit, which was about to create a black hole that would destroy the Earth, but was defeated by the Extreme Gear riders.

History
Near the end of Sonic Riders: Zero Gravity, SCR-HD appeared at Crimson Tower and stole all five Arks of the Cosmos from Wave. Still acting according to the objective given from the Arks of the Cosmos, SCR-HD brought all the Arks of the Cosmos back to Babylon Garden. This transformed Babylon Garden into Astral Babylon and made the core unit of Babylon Garden create a black hole that threatens to consume the planet. In the process, through the Arks of the Cosmos' influence and power, SCH-HD merged with the core unit and transformed into the twisted Master Core: ABIS.

Soon after transforming, Master Core: ABIS was confronted by Sonic, Jet and their respective teams on the Mobius Strip, who had come to disconnect the core unit and stop the black hole from destroying the world. Master Core: ABIS fought back however, and tried to use the Arks of the Cosmos' gravity manipulating abilities against them. Sonic and his allies, however, used this power against Master Core: ABIS and managed to defeat it. This resulted in Master Core: ABIS being consumed by the black hole it had created, thus disappearing into nothingness.

Powers and abilities
By absorbing the energies from the five Arks of the Cosmos and the core unit of Babylon Garden, Master Core: ABIS is granted powers and abilities far beyond its normal form. Thanks to its connection to the Babylonian's gravity-harnessing technology, Master Core: ABIS can manipulate gravity. allowing it to perform Gravity Drive, but on a much larger scale than most others, and can completely distort gravity in a large radius, resulting in the environment being torn apart through gravity shifts.

Additionally, Master Core: ABIS can form large yellow energy bolts and shoot them at its opponents. It can also create and gather giant blocks of molten rock and throw them like meteors at its opponents, which create large explosions upon impact. It also has the ability to teleport over short distances.

Battle
The battle with Master Core: ABIS is similar to that of the Babylon Guardian, but is considered less frustrating, if not slightly harder. It has a five minute time limit in Story Mode and also it has six hit points, which is double of what the Babylon Guardian had and the only way to hit it is to take advantage of its Gravity Dive and hit the sphere underneath it, similar to the Babylon Guardian's vase. Each two attack is considered a lap and from second lap. The Master Core starts shooting energy balls or throwing meteorites. Other characters can hit the Master core too, but it is only counted when the player him/herself hit it. The player must try to be the first place to hit the sphere first and complete the game under five minutes during the story.

Trivia

 * Master Core: ABIS' name is derived from its symbiotic relation to the black hole's core and "abyss", a common term for a seemingly-endless stretch of empty space.
 * Master Core: ABIS somewhat resembles Metal Overlord.
 * Additionaly, this is also the second final boss based on a gigantic robot that Sonic faces, the first being Metal Overlord.
 * It is possible for SCR-HD to fight Master Core: ABIS, despite that the Master Core: ABIS actually being SCR-HD.
 * Master Core: ABIS may have six hit points in Story Mode, but if this course is chosen outside of said mode and is set to race 99 laps, the player is required to hit the boss a total of 198 times in order to finish the race.
 * In a normal race, if the player selects to do one lap only, Master Core: ABIS will only use the attack where it tosses meteors on to the track.
 * Master Core: ABIS' appearance differs between the two versions. In the Wii version, his face is completely metallic, while in the PlayStation 2 version, his face comprises a bunch of wires and a glowing red dot.
 * Master Core: ABIS mentions Devil Doom from Shadow the Hedgehog because both are final bosses, have an asteroid attack, and have a torso with arms and a huge ball-like lower body. However, Devil Doom has two heads and is organic and Master Core only has one head and is a robot.
 * Master Core: ABIS seems to be the resurrected guardian from the previous game, as ABIS makes a strange noise when the player starts the race with a character and extreme gear.
 * It is impossible for the player to use Super Sonic in this battle, as he runs on rings to race and any mean of granted him would result in failure and glitches if the player finds a way to use him, such as hacks.