>>538144018
Sandrone is Alain is my theory. He managed to transfer his consciousness and kept working with his robots hundreds of years later.
Whereas Pulonia is just a storage of where the real injured Mary Ann sleeps. The Oceanid didnt absorb Mary-Ann properly and only took her spirit or mind and the real Alain was obsessed with saving her but it turns out he's been protecting an empty shell this whole time.

What are the chances that it turns out that Sandrone is completely unrelated to Alain and Mary-Ann?

Mary-Ann was the true gigastacey.