In the end I decided to realize the whole scene as a 3D full CG shot. This allowed me to work better with lights, effects, explosions and fogs, which I placed a lot of in the shot to increase the dramatic atmosphere. I tried to make the best possible connection with the already shot footage.
The technique I used was hybrid 3D matte painting combined with 3D environments and 3D animated robot characters. All in Maxon Cinema 4D. I then did the full compositing of the large amount of layers in BlackMagic Fusion and the final editing touch in Davinci Resolve.