[I've piloted a mecha myself, so this isn't made up or based on wild assumptions.]
[Multiple female leads. The protagonist isn't a bleeding heart. He's a good person, but not the traditional flawless paragon. He won't be guilt-tripped into acting morally, nor will he make selfless sacrifices.]
Jiang Jian Yue is a medical student, but he's never studied any medical knowledge and can't treat or diagnose illnesses.
That's because a whole new kind of “virus” has descended upon Earth from beyond the stars. Any animal or human infected by it turns into a man-eating monster.
Jiang Jian Yue's job is to use his mecha as a scalpel and physically send these virus-carrying monsters to the afterlife.
But as Jiang Jian Yue keeps destroying monsters and growing stronger, he discovers that two races descended upon Earth in the beginning. The kings of both races are twin sisters, each in control of either “authority” or “power.” Yet neither can gain the full measure of “power” by devouring her sister, so they have to find another way... and Jiang Jian Yue is drawn into the vortex as well.
“I can save people, but dispensing medicine and treating illnesses? No way!”
“As long as I'm still standing here, no one can take my power away from me.”
