Blackheart appears to look just like Sonic the hedgehog only more of a 'darker' image from the blue-blur. His body is made entirely of dark fur with what appears to be golden gauntlets on each hand. His boots are the same color as his gauntlets but they appear to be metallic and not from any kind of metal on Mobius. His eye color appears to be dark grey but flaring green when taunted by an opposite sort of foe (a hero). His mouth always shows his 2 kanine teeth with blood that never wipes off. His fur never changes color due to him using special crystals in his past that granted him dark magic for the deal of sending him to Hell and letting him wreak havoc in the pit of fire for his eternal life. His vlothing consists of nothing but armor unlike most actual heroes and villains on Mobius. His armor seems to have cuts in it that release green light giving him the use of dark magic. His armor is also something that Mobius has never studied making it hard to weaken Blackheart. Blackheart also has wings but unlike his main body the wings are made out of dark magic granting him flight when he needs it.
Blackheart can be... very non-emotional when around even people of his own kind. He never find the motivation to smile nor does he find any emotion in his body but the will to create punishment for whoever gets near or whoever is around him. Due to him having no heart, Blackheart wishes for all life to be stuck in eternal punishment for the rest of their days. Whenever he feels his territory being threatened, Blackheart does not ask questions but rather leaps into action to kill whatever had upset him. His lack of free will is what drives him to his emotional distance from the rest of Mobius.
Blackheart used to be the grand leader of all the Mobius back in times when the echidna tribe was still being constructed. His life was soon torn down after his father, Nightrush, had come to take the throne from his son. Blackheart grew angry that his father was gaining everything from him ever since the birth of the monster. Knowing his father would least expect it, Blackheart quickly did what no other Mobian dared to do. He made a bargain with the underworld a.k.a Hell. Blackheart did not know what he had done due to the devil himself dragging Blackheart into Hell to complete the deal. Blackheart had wished for the power to destroy his father who was now the new king of Night-Topia. Blackheart got his wish and was sent out of Hell to find his father. He had soon found his target and initiated war on him but failed. Wanting more power, Blackheart went to destroy his father but he never got the chance. Before he fleed in bloody shame, Nightrush told the devil to make a new deal with Blacheart. Nightrush did his part and Blackheart soon found out he was tricked, being sent down alive into Hell. The black hedgehog was yanked of his heart but got to keep his soul for purposes unknown. For years now, Blacheart has been ruling the underworld/Hell for as long as he can remember. Every few years he is set free to wreack havoc on Mobius now gaining his respect for his father for being such a loyal king. Soon enough, Blackheart had absorbed much dark magic in the basic nature of 'evolution' giving him the powers to finally destroy his father... but that was no longer his intentions. His new goals were to destroy anything that enters Hell to save a soul letting the devil of himself sleep peacefully knowing another strong demon is destroying all the angels who enter the pit of fire.
Damnation - Blackheart unleashes his burning breath onto his targets with ease making it much more easier to lay a critical hit on his opponent without the worry of him/her moving around a lot.
Corrosive Bomb - Blackheart can release corrosive (acid) particles into the air from his mouth to burn his opponent(s) from afar.
Dive-Bomb - Blackheart charges fire into his body and uses dark magic to fly into the air. When air-born Blackheart dashes down to the ground at great-neck speeds, smashing it, causing fire to explode from beneath his feet making an echo flame ring that stretches 55 ft. Dodging is very hard as Blackheart has very sharp eyesight.
Spin-Dagger - Blackheart can become an inferno of blue fire and spin-twirl in place releasing flame daggers from his inferno twirl. When twirling his body will be untouchable without taking damage meaning that dodging the daggers is the best solution.
Bloodwing - Blackheart can propel into the air using his inferno twirl and release sharp bloody daggers from his flaming body. After they are released, Blackheart will attempt to bash into the ground to claw his opponent using his sharp claws.
Inferno-Twirl - Blackheart turns into a bolt of blue fire and quickly twirls towards his opponent like a twister. If touched by any type of opponent (besides one with a shield), his twirl will release damage and wrap flames around his opponent causing burn.
Bloody Melee - Blackheart releases a combo of claw slashes at his opponent then quickly wraps them in fire causing his attacks to create a more critical effect on the enemy.
Grind - Blackheart can grind of anything that looks like a rail. His speed is much faster then Sonic when it comes to grinding.
Smashing - Using his inferno twirl, Blackheart can destroy anything from wooden to pure steel even the strongest door with the help of his dark magic.
Strength - Blackheart is able to lift vehicles, platforms, boulders, and anything equaling the weight due to his strength. Having this much strength also makes him a worthy adversary to Knuckles, Rouge, Vector, and Storm.
Pyrokensis - Just like Blaze, Blackheart can create fire at will thus making him a master of pyrokenesis.
Spin-Jump - Blackheart can jump in spindash formation the same way that Sonic the hedgehog can making him very hard to attack when air-born.
Due to having dark magic on his side, Blackheart can easily use certain moves as his advantage to counterattack, he can also avoid such effects on himself such as pyrokenesis and pyshikonesis. His strength makes him a worthy match against all power/strength type characters. His speed makes him a formidable foe against Sonic, Metal Sonic, and Shadow. His flight makes him a very challenging foe for Rouge, Tails, and Wave. He is marked number 3 in one of the most challenging foes that Sonic and his friends have ever faced.
Water - When in the water, Blackheart's powers grow to be weakened as his fire is no longer usable and his running is decreased by half.
Electricity - When near electricity, Blackhearts powers seem to be weakened and his dark-magic appears to be much harder to control making it a challenge for him to fight anybody.
Melee - Most basic attacks can still lay a hit on Blackheart but powerful attacks on his chest can leave a critical hit on the hedgehog.
Dr. Robotnik - Dr. Robotnik once met up with Blackheart after releasing him from the underworld. Due to trying to save Blackheart from being pulled back into Hell, Dr. Robotnik has made his way into being a friend with Blackheart.
Scourge the hedgehog - Due to helping Blackheart attempt to gain his kingdom back (but still failed), Scourge has made himself appear as a friend to Blackheart.
Mephiles the dark - After learning about Mephiles and how he nearly killed all of Mobius, Blackheart has grown amused by the dark being and is an ally to Mephiles whenever such an emergency or team-work moment comes into play.
Sonic the hedgehog - Mainly, Blackheart is an enemy to Sonic and all of his friends due to himself wreacking havoc on Mobius at a time when they happened to get in the way and stop the chaos from unfolding. Blackheart vows himself to one day destroy everything that they get in the way of when he is around.
- Blackheart rarely helps Sonic, but when he feels a common threat involved, Blackheart will do anything to stop it including if he must join the blue-blur and his friends.
- Blackheart was born with anger due to Nightrush drowning him in a volcano of black fire before birth which also gave him his fire abilities.