Breg was looked down on by most Saiyans because he had a laughable power level. He was, however, very intelligent. He plotted for years to take over Vegeta and enslave all the other Saiyans with his god-like technology. He could cloak things to make them invisible, make power levels undetectable, and had even created teleportation devices. Mere months before he could unleash his wrath, planet Vegeta was destroyed, and he narrowly escaped the blast in a spacecraft.
He knew the Saiyans had a bad reputation and he wouldn't have many allies, so he kept his identity a secret evn though he knew some other Saiyans had survived. He lived alone for many years in an asteroid base until he started sensing incredible energy around the Earth. He went to the planet, making sure he looked like one of the locals, and discovered Goku and his friends. He took on the alias of the human scientist Doctor Hiroka and began studying Goku and the others. He was set on becoming just as powerful as these Saiyans and conquering the universe, but knew he had to do it in secret and not reveal who he really was until the very end.
He designed a satellite to observe the Z Fighters and a secret underground base for training and experiments. The base had a special chamber that kept the Z Fighters from sensing his energy. He finally developed a machine that could increase his power level as he saw fit, and a bracelet to hide his power from the Z Fighters. He discovered through some calculations that if he tried to turn the machine to full power too early, the power would kill him. He had to train for years to keep up with the Z Fighters, and to his frustration, they always seemed a step ahead of him. He tried pushing himself to the brink of death several times to try and increase his power, but to no avail. When Goku and Vegeta became SSJ4s, he decided they were too powerful for him to keep up with. He decided to try and increase his power beyond SSJ4 and destroy them then and there, even though he knew his body couldn’t take it in its current state.
When he started up the machine and turned it to full power, it broke his machinery, letting the Z Fighters sense him. When Goku, Vegeta, and Piccolo came to investigate, they found him in the corner of his lab curled into a ball. When they noticed his tail and demanded to know who he was and how he had been hiding for so long, he said it would make no difference if they knew. After he was done telling them he laughed at their confusion. He gloated.
“Now you see how brains are sometimes better than brawn! Thankfully, now I have both! Behold my new power!” He pressed a button, opening the roof of his laboratory. The full moon shone above him. “I, Breg, am not a Super Saiyan Four! I have become something more!” He looked up at the moon and began to transform, but not into an Oozaru. He first became a SSJ4, and then he began to grow claws and sharp teeth. He began to growl like an animal and slowly grew into a monstrous creature that looked like a cross between a SSJ4 and an Oozaru. He looked down at his hands. “The power… It hurts… No!” He began foaming at the mouth and scratching the walls. His voice got deeper and more gravely. “I was so stupid! If I had trained more, if I had waited…” His eyes glazed over and he looked down at the three warriors with a violent glare. “Die, now.”
Breg has twice the power of a SSJ4. He is twice as fast, twice as strong, twice as durable, etc. His fighting style is very animalistic. He claws at his foes and even bites if necessary. This makes him unpredictable and hard to fight back against. He’ll often charge on all fours, barreling through his opponents, or use his tail to grab foes and toss them like ragdolls. His claws and teeth are sharp enough that he’s able to cut and puncture just about anything.
Mouth Blast- This attack is a beam of red energy from Breg’s mouth that has destroyed entire planets.
Burst Blob- This attack forms a red blob of energy that can be of varying shape, size, and power. The blob will break when Breg clutches his fist. One of his favorite ways to kill is to force a burst blob down his foes throat and detonate it inside them.
Armageddon Fist- Breg will only use this as a last resort. He focuses all his power into his fist and releases it in a punch. When he used this attack it destroyed an entire galaxy and reverted him to his base form.