You build the Great Wall of Introduction. Dedicated bathroom for puppy, for well puppy reasons and that Annunaki only gives up "minor" territory at first.
Let them interact through the mesh at their own leisure like pictured. Feed them treats nearby and reward them for non-hostile behavior. Watch the ears and tail!!
Periodically put Annunaki in a room (depends on their comfort if it is with someone else) and then allow the puppy to explore for a half hour or hour, then go back to the same arrangement. Annunaki will start sniffing around. This is to start mingling their scents around gradually and guaranteed Annunaki will return back to the bathroom at some point for more evaluation.
After the first day or two, you may expand the territory of the puppy into a bedroom and bathroom by moving the wall. Periodically swap them once or twice a day so they can introduce their own scents. This will be stressful for Annunaki so do it in moderation.
Personally, I slept on a cot for the first two days in the bathroom before I had to bring down the wall. On Day 3 I had the master bedroom and bathroom as quarantine for Isis but the boys were simply too inquisitive at this stage with no aggression and it's been perfect. You'll know when both are side by side of the mesh and you can interact with both with no hostility.
There are plenty of high places for Annunaki to go once you get to this stage and bring down the wall for good. Let Annunaki get in swats to establish dominance those are extremely, extremely valuable lessons for the puppy on how to get along and respect cats.
Good luck!