I think the reason why imu has been putting up with the retarded celestial dragons is clear now
Like, they are all useless whiny bitchass rich entitled inbred fucks. No need for imu to tolerate them
I think the reason he lets them be around in marie joa is because they are his army
In the final war, imu will turn all celestial trash into Demons. That way, the good guys will have an army to fight. And the bad celestial dragons will be taken care of. No need to write their fates out if they all die from demon mode soul cost.