There were five days left until Cell mastered his power, and with nothing to do during this time, Wei Dong wondered if the system would allow him to travel back and then return again.
"It is possible, Host." Hearing this, Wei Dong immediately had the system transport himself, Son Goku, and Gohan back to their original world.
With a whoosh, they entered the Hyperbolic Time Chamber of their original world.
After entering, Son Goku asked, "Aren't we only allowed to stay for two days? Doesn't it matter?" Wei Dong replied, "That was the world of future Trunks; this is our own world, so it doesn't affect anything. We can continue to enter."
"System, can the Battle-Hardened skill be upgraded?"
"Yes, Host. It requires 50 system coins. Since you obtained it through a mission, it would have cost 100 system coins if you had exchanged for it previously."
"Alright, System, then upgrade it."
"Host has 180 system coins remaining."
"Then upgrade it one more time."
"Understood, Host. You have 80 system coins remaining."
Battle-Hardened is now level 3. I wonder how the boost will be; constant combat must provide an insane increase.
"Let's start training, Son Goku." Son Goku replied, "But I want to teach Gohan how to become a Super Saiyan 2 first."
"It's fine, Son Goku. As long as we keep fighting and our base combat power is high enough, we won't need Super Saiyan 2. Just keep fighting to raise our base combat power."
"Hmm, then let's start combat training." Two years passed. "Goku, our time is up; we need to head out."
At this point, Wei Dong's base combat power had reached over 98 million, nearing 100 million. Son Goku's base combat power was over 69 million, while Gohan—perhaps due to constant training—had a base combat power of over 73 million, even higher than Goku's. Goku finally realized Gohan's potential.
"Grab onto me; we are traveling to the world of future Trunks again."
After arriving in the world of future Trunks, they could not sense the presence of the Z Fighters. "Goku, do you feel like something is wrong? They might be in the Hyperbolic Time Chamber."
Using Instant Transmission to arrive at the Hyperbolic Time Chamber, they found no Z Fighters inside. Instead, there were two figures and a pile of debris.
Indeed, these two were Cell. Both were in their Perfect forms—one was the Cell from their world, and the other was the Cell from the future world. The two had joined forces.
"What should we do, Wei Dong? These two have incredibly powerful energy signatures."
"One Cell has 4 billion combat power, and the other has 6 billion. No, that's impossible; Cell shouldn't be this strong."
Why was there such a massive gap when both Cells were clearly in their Perfect forms?
One Cell spoke, "I am the Cell from your world. I spat out the future Android 17 and Android 18 to let him evolve into his Perfect form, and then I absorbed the Android 17 and Android 18 of our world. That is why my combat power is so immense."
"Rest assured, we haven't even used our full strength. During our time in the Hyperbolic Time Chamber, we used our Saiyan genes to grind combat power—beating ourselves to the brink of death and then using the Namekian regeneration ability to recover. That is why our combat power is invincible."
After speaking, Cell began to power up, his energy rising continuously. One Cell reached over 9 billion in combat power, while the other reached over 7.5 billion.
"Son Goku, Gohan, are you confident in taking on one of them?" "To be honest, if Gohan can transform into a Super Saiyan 2, he should be able to hold off the weaker Cell."
"That's no problem. I'll take on the stronger Cell." In an instant, the battle began.
Wei Dong transformed into a Super Saiyan 2, his combat power hitting 10.7 billion. He didn't gain much of an advantage against Cell; they were evenly matched, though Wei Dong was holding back intentionally, hoping to trigger Son Gohan's transformation.
Things were different for Goku and Gohan, who were immediately pushed onto the defensive. Son Goku transformed into a Super Saiyan 2 with 6.9 billion combat power, while Gohan could only transform into a Super Saiyan 1, leaving him with 3.65 billion combat power.
Consequently, Goku and Gohan were quickly overwhelmed. Cell had no intention of killing Gohan; instead, he kept torturing Son Goku while toying with Gohan, as Gohan's combat power wasn't enough to land a hit on him.
Goku was soon driven to despair by Cell's attacks, while Cell stood to the side, mocking them incessantly.