I'm wondering why Imu didn't use that sword to begin with. It could be that the polearm is just a different combat style. OR, this blade is stronger, but it takes a lot more "Omen" or stamina out of Imu, so he is using it sparingly, as not to be sent back to Mariejois.
If that is the case, I assume Imu has much more up his sleeve, but he can't show it due to him being away from Mariejois.
If that is the case, I assume Imu has much more up his sleeve, but he can't show it due to him being away from Mariejois.