System novel + single heroine + invincible + not a goody-two-shoes + feel-good power fantasy
After transmigrating, Lin Yu, an ordinary college student who had just graduated, was suddenly whisked away by a System to an unknown world. He had hoped to make his mark there, but the System worried he was too weak and might die the moment he stepped outside, so it forced him into a sleep lasting fifty million years!
Many years later, Lin Yu woke up and looked at the somewhat familiar planet before him, along with the familiar monsters on its surface. He couldn't help letting out a sigh.
Wait, Golba? How come nobody told me this was the Ultraman universe?
But it doesn't matter. I'm a cultivator, after all. I'm no pushover!
Dark Giants? I'll subdue them by force! Ancient monsters? One punch and they're done!
Monsters: Why is this guy so terrifying?!
Trigger: Next to him, I'm practically an ordinary person!
Z: Before meeting Lin Yu, I never imagined a human from Earth could possess such incredible power!
Lin Yu: As someone at the Qi Refining stage, it's perfectly reasonable for me to cultivate primordial purple qi, right?
It's good, but even someone as strong as you can let the opponent escape. Every time you fight, the opponent gets away!
There's a big problem with your approach. They're all like pilots of Gundams. How could such a cultivation technique possibly be found in any of those few dark giants?