Disclaimer: I do not own/am not affiliated with DBZ in any way
A/N: In this world, instead of Dr. Gero focusing on building the Androids, he saw other strong fighters at the World Tournament and decided that he would build a mind control device and use it to turn Goku's friends against him and ultimately kill him, because Gero knew that Goku's kindness would never allow him to kill his own friends and he would have no choice but to die. This story begins in between the gap between DB and DBZ, more specifically Age 759, a little over two years before Raditz arrives on Earth. Also in this timeline, Gero is already slightly robotic in the sense that he is stronger than the average human but isn't nearly at where he is in DBZ, consider him a prototype of a prototype. Anyway, enjoy!
"Finally, it is finished!" Gero proclaimed as he marveled at the device capable of making even the strongest warriors bloodthirsty murderers. The device looked like a crown that was pretty similar to what Broly wore on his head. However Gero, in all of his genius wisdom, had programmed the device to morph into the user's body as it took over his cells, which Gero had estimated to be somewhere in between 3-6 months.
Gero turned around and looked at his graphs to look at Goku's most ferocious foes to see which one he should control first, the first name appearing on his list/graph was in all capital letters: PICCOLO. Below it were listed his weaknesses and strengths and as Gero analyzed this, he saw that he may not be able to control Piccolo immediately as his stubbornness coupled with his power rivaling that of Goku, he would have to surprise Piccolo to put the device on him and even that might not work.
Gero continued to look down the list, which contained more than just Goku's rivals/former rivals, also containing Krillin, Roshi, and Chi-Chi, three of the other strongest warriors, although being a little below Tien, Yamcha, and Piccolo. Gero analyzed the other 5 to choose and after a few minutes of heavy analysis, Gero ultimately decided that the one he would attempt to use his mind control on first would be: TIEN SHINHAN.
"Mr. Tien, can we be done for today?" Chiaotzu asked innocently, "my arms are numb from the cold and I'm so tired," he said as stumbled on the ground.
Tien, who was slightly annoyed at the interruption to his training, smiled slightly when he saw Chiaotzu, the only person that had ever made Tien smile. "Sure, Chiaoztu, go back home and gets some rest. As for me, I'll be done in a little bit, the next time I see Goku I want to be a lot stronger than I am now," Tien said as Chiaoztu gulped, nodded, and turned back towards their log cabin that stood out amongst the cold and icy whit of the glaciers. As Tien saw Chiaoztu near the cabin, his face returned to its normal ferocity as he raised his right index finger and shouted "Dodon Ray!" as his yellow beam shot from the tip of his finger and annihilated a small nearby ice block. Damn, Tien thought as his breathing became sharper, it still isn't nearly where it needs to be. Goku would easily be able to dodge it and even if he didn't he could easily overpower it with his Kamehameha Wave. And then there's Piccolo... He would have killed me by now! Tien opened his violently and shouted angrily as energy poured out of him and a vein stuck out from his neck and forehead, "I will, no I must get stronger!" Tien several of the other nearby ice blocks and by the time they were all destroyed, he was spent. He struggled for air as he dropped to a knee and his head dropped.
Nearing the glaciers, Gero felt the vibrations of the explosions caused by Tien, "wow," Gero said as he checked the power emanating from the explosion, "was my data exact?" Gero asked himself, "it doesn't seem accurate that this Tien Shinhan had nearly this power when he last fought Goku," he said and sure enough as his data quickly updated, Gero saw a sharp increase in Tien's strength, enough to alarm Gero, "he still isn't quite at Goku's or even Piccolo's level, but his power maybe too much to control, especially considering that this mind control device may not even be truly complete," and for the first time Gero realized that he was risking his life to try out this new device to defeat Goku.
At this point, Gero was near enough to see Tien on a lower glacier and Gero stealthily continued to move in on Tien and as he watched, he smirked slyly as he saw Tien struggling for his breath on one knee. Good, he thought, I can sense that Tien is running on low energy and seems to have let his guard down. Gero got out of his robot, that he had specifically used to survive in the icy cold of the glacier and he tightened his fur coat around his neck as he continued to slowly move closer to Tien.
Tien didn't even see it coming as he looked up, he saw hands clawing over his mouth and nose as he struggled but in his weakened. surprised, and exhausted state Tien couldn't push the force of off him in the few seconds he had and in a few more seconds, Tien felt himself lose control of his own mind as his consciousness faded to black...
As Tien awoke in his chamber, Gero opened the door as Tien slowly walked through and as he did Gero asked him, "so how are you feeling Tien Shinhan?" In a stern voice.
Tien rubbed his head for a moment seemingly not knowing what was going on but as Gero tapped his index finger above Tien's closed third eye, Tien's two open eyes turned blood red and in a mechanical voice he said, "ready to serve you, Dr. Gero."
Gero nodded and smiled menacingly, " and what is your main objective?"
Tien's eyes returned to their normal state but he retained the aura of evil and said in the mechanical voice, "main objective: kill Goku."
Gero's eyes narrowed, "good... but there is still more work to be done before that goal is reached...