Tier

Strength system.

Tier 10 : Ordinary people - athletes .

Tier 9: Strong enough to destroy wall - a small house.

Tier 8: Strong enough to destroy large buildings - a small mountain.

Tier 7: Strong enough to destroy a large mountain - a small city.

Tier 6: Strong enough to destroy a large city - a small island - a large island.

Tier 5: Strong enough to destroy an entire country - a small continent - a large continent.

For the time being, we will stop here. I think the characters in the One Piece world will have powers at these levels only.

I estimate that the top strong characters of One Piece will have the power at Tier 6 or the highest at the low end of Tier 5.