Imu is actually asking Gaban is he truly believes in the "luffy is the man we've been waiting for" thing.
Then Gaban confronts him saying he also believes that.
Translating from japanese is not the easiest thing because it is a fundamentally different language structure. But the way people know that top left speech bubble is from Imu, is due to his speech pattern.
Also, with these AI translation slops that a bunch of groups are using in order to be the "first ones to publish it", it becomes even more annoying.
Saw a translation that, instead of saying Stigma when trying to attack Luffy, Imu says "Enma".
LMAO.