It was a 6 weeks now after the fight Roy and Tai had and Roy has been training with Vegeta ever since. They weren't at the fighting arena of where they met. Apparently Vegeta had a special place for Roy to train.

"This is where I train. I used a room like this and first transformed into a Super Saiyan. Maybe it will do the same thing for you." Was what Vegeta told Roy when they entered the room. It was a dome like room with some kind of generator in the middle of it, towering to the roof of the dome.

"This is a gravity amplifier room. The gravity in this room will increase, make you try hard to fight. If you can do well with a lot of gravity coming down on you, you'll be able to attack with great speed and power" Vegeta explained all those weeks ago. Roy gave a smirk that day, and agreed to train here.

His wounds were still healing from the attacks Tai gave him, but he trained anyways, determined to beat his two rivals, especially Tai. He started easy with gravity amplified 5 times. He was able to master his attacks within an hour of training. As weeks went by, Vegeta and him trained together, gravity growing heavier and heavier, harder and harder for him to train, but he kept going. The anger inside him drove him to grow stronger than anyone in the Academy.

We're now in the sixth week of Roy's gravity training, and he's now training in gravity amplified 100,000x. He was attacking Vegeta with numerous attacks, but all of them couldn't hit him for he was too quick for him. Vegeta gave a Roy a blow to the face, knocking him back a few yards away on the ground. Vegeta stood near him, scowling at him.

"Get up Roy! At this rate you won't be able to beat Tai or Souske! You must drive yourself to be strong! Otherwise you'll be weak for the rest of your life!" Vegeta yelled.

Roy got off his back, and yelled back "You think I don't know that? I am driving myself! More than you can imagine!" and then Roy shot a ki blast at Vegeta, but Vegeta deflected it easily. Roy was now trying to get himself up, his body shaking in pain.

Goku crept inside the gravity control chamber, watching Roy and Vegeta fighting. Well, just talking right now.

"I don't believe it one bit!" yelled Vegeta. "You're only driven to beat up weaklings, not the strongest! If you don't want to fight the best you'll only be second best! Tai and Souske drive themselves to be the best fighters around!"

Roy then yelled in anger, and he instantly transformed into Super Saiyan 2 and screamed "Shut up! I'm sick and tired of everyone comparing me to them! I am a much greater fighter than them, I've been here for years! They only been around for a little over a year and they get all the praise! Took me forever to get that kind of respect! NO MORE!"

When he yelled 'No more' a burst of energy came out of him and transformed into a Super Saiyan 3. Vegeta was now getting worried, and could feel Goku's presence, knowing he was getting concerned too.

"I'M GOING TO SHOW EVERYONE ONCE AND FOR ALL WHO IS THE BEST AROUND HERE! AHHH!!!!!"

Roy's energy became rushing out of him like a flood of waters, destroying the equipment in the room. Vegeta stood his ground, Goku rushed over to his side. "What's going on? His power growing at an incredible rate!" Yelled Goku.

"I don't know! His anger is releasing his power!" Vegeta yelled back.

Roy was emitting an aura that destroying everything in the aura, his power becoming destructive. Then after one powerful cry, his aura flashed and exploded, knocking and flipping back Vegeta and Goku right on the ground. Vegeta recovered from the blowback and got right back up, while Goku stopped himself from flipping over again, and then got back up. The whole place was covered in smoke, only seeing Roy as a shadow, standing there quietly. Goku made a force blow to remove all the smoke, and became frozen in shock at who they were looking at now.

Roy was no longer in Super Saiyan 3 form at all. Now he was wearing a black cloth pants with his training boots, but no longer wearing his shirt but his chest was covered in blood red fur with only his torso area clean of fur, and his hair was pitch black instead of blonde, with much volume and going in all sorts of directions. His eyes were now black with his pupils' red, looking at the two with such horror inside them.

"Kararot… Roy… he turned into…" Vegeta was saying, but couldn't continue with his words.

"A Super Saiyan 4…" Goku finished, but something was different about this form of Super Saiyan 4. Didn't look like the kind him and Vegeta turned into.

Roy then looked at himself, showing a amused expression. He opened his grin and said "So this is what true power feels like…" and then he charged his aura, making the two warriors flinch. Roy's grin became wider and he said "Now I can kill those two idiots once and for all, and anyone else who gets in my way." and then he shot a powerful blast right at the roof, destroying it completely.

Roy then turned to Goku and Vegeta, smirking devilishly and said "Now if you excuse me, I have some killing to do."

Goku took a step forward and said "We won't let you do that, Roy." Then Vegeta took a step next to Goku and also said "Not if we have anything to say about it."

Roy's smirked then showed his teeth, which showed that they were sharpened. He replied "I don't think you won't be able to anything about it." And swiped his hand through the air, and then a crimson energy dome went over Goku and Vegeta. "Thanks Vegeta for showing my true power. I'll be off now." And disappeared in thin air.

Goku turned to Vegeta and said "What just happened? Why does his power level feel some much higher than ours in that form?"

"Because it is, Kakarot." Said Vegeta. "He's has so much power inside him that he was able to transform into a Super Saiyan 4 without turning into a Golden Ape. But this transformation is much different from ours. He turned into Super Saiyan 4 through his ambition for revenge. That is a Super Saiyan form of evil. It makes him more powerful than we ever could…"

"Could this be the power of a Forbidden Saiyan? Going at Super Saiyan level we could never achieve?" asked Goku, frantic.

Vegeta slightly shrugged and said "Maybe. All I know is that we need to get out of this dome before he kills someone or he gets kill himself."

Goku nodded and said "Right, I think one good punch would be able to break it," and then Goku gave the energy dome a powerful punch, and it shocked him, knocking him back. Vegeta rolled his eyes and shot a energy beam at it, but it bounced back right at him, also shocking him and knocking him back. The two warriors looked at each other and Vegeta said "So what do we do now?"

Goku gave Vegeta a determined look and said "All we can do now is hope Roy can be stopped. All we can do now is rely on Tai and Souske to put an end to this."