So let‘s try to summarize
Imu has •“ shadow blob form“ let‘s say similar to Doffy‘s string clone.
That blob form was capable of DR Xebec.
At Elbaph Imu takes mind control over Gunko and DR Elpabh with the help of his book and the guns.
Then we found out that DR can be cancelled by •killing each other“
Then we find out Imu‘s shadow blob with Gunko knows that he can‘t DR Loki and Luffy yet he tries it anyway and try‘s to explain why it won‘t work but get‘s no diffed by them.
My assumption is, especially after his talk with Gorosei, only Imu‘s real form COULD THEORETICALLY DR them both. And even then it‘s not even certain that he is actually going to Elpabh.
I despise DR, Imu and finally Oda. Horrible story telling