I'm not sure if this is the right thread for this question, let me know if I should ask it elsewhere
How powerful do you think Jack is, compared to Doflamingo? Do you think he's stronger than Doffy, or does Doffy have the strength of a Yonko commander? If he's stronger it's gonna be a hell of a fight when they will face Kaido and his calamities!
This is a difficult question to answer.
First and foremost, we didn't have a full picture of the fight between Jack and the Minks, particularly Jack with the Mink rulers, Inu and Neko. When the StrawHat initially came to Zou island, they were faced with Carrot, Wanda and a few good fighters there. From their brief encounters, we were able to have a rough idea of how strong the Mink people are. Further to the story, we were told that the Mink race is a tribe who are trained as warriors since young. From these bits and pieces of information, I reckon that the rulers must be powerful enough to face any threats that come against them. Furthermore, the manga appears to portray them as very strong and powerful people.
During the days of the battle, Jack has been fighting day and night with the two rulers non-stop, and none had won the battle. We were also told by the Minks that Jack had appeared to lose his patience and that was why he used the "poison gas" which resulted the defeat of the Minks. I suppose both parties were on "fist-to-fist" during that battle and not even one party won the battle. It was only after the initiation of poison where the physical fight stopped.
If we take Jack and compared him with Doflamingo, in terms of physical strength, I suppose Jack may have the upperhand. It seems like Jack is more of a physical fighter, while Doffy is more of a manipulative type and he uses strings and not so much of fist. It is really hard to tell unless we can have a closer look at Jack and see how he fights. We have only seen Doflamingo in detail during the Dressrosa arc. But Jack is still quite a blank page for us. Perhaps when the author shows us more in future, the topic as mentioned may be more relevant. Truly, we can only speculate at this point.
Thanks for bringing up for discussion.
