Yeah the question of “is imu the final villain” has definitely been answered. The only question left is what is Imu. And how does he fight.
How does "she" fight.
We've already seen Imu "flex". Probably they "fight" by unleashing the destructive power they just demonstrated.
So opening their eyes and unleashing Heavenly Judgment.
As for "what is Imu?", some guesses (in no particular order):
- The Ancient Weapon Uranus
- A god(dess)
- A mythical or ancient race/lineage
- A descendent of the Ancient Kingdom
- A ruler of the Ancient Kingdom
- A prince(ss) of the Ancient Kingdom
- A several hundred years old being
- The most powerful character in the story
- The final arc "princess"
- The queen of the world
(The above guesses are deliberately not mutually exclusive.)