>>283639261
Well to be fair, they didn't beat her. Like she definitely would've won if not for a trap. Kaido got overpowered aka beaten by Luffy. Both were defeated, of course, but as far as strength goes, Big Mom wasn't taken out out by anyone. It's like a reigning heavyweight boxer champion falling to a volcano through a trap door thanks to a amateur boxer's trickery. He won, but not by "fair play". That said, pirates and all.

>>280322075
Nami's eyes has one ring
Imu's eyes have two ring.
Oda has never drawn Nami's eyes with two rings
Many characters like Robin, Hancock,Big Mom, Cavendish, Caribou, Zou and Mihawk has two ring eyes in one piece