Imu is hijacked by the awakened devil fruit
1.Its a devil fruit that rules the entire world, an awakened "devil" devil fruit.. somehow it can possess people. Especially the original 20 kings who made the world government. Maybe they got cheated or willingly made an agreement with the devil. Imu kept their bodies in some kind of dark dimension and thus appear as amalgamation of these bodies as a blob
In Gunko's case its only a half possession, maybe she didn't Fully give in . Anyway imu underestimated elbaf and sent gunko first, believing this half possessed vessel is sufficient to achieve goals. But the plan failed. Also notice her eyes changed and got wings and tail after the possession of imu
After the plan failed. Imu directly pulled up in Elbaf. But the cost is severe cant maintain the blob like body. Had to revert to a stored up body of an ancient king ( thats the lunarian figure in the latest chapter). And the imu (the devil fruit) had to transform a chakra made of black fire with eyes behind the new figure. Imo that explains why the memory lag and the new imu is acting weirdly unlike the blob or possessed Gunko.
My bet is the blob (awakened devil fruit) and the vessel the new imu are different entity