Details of the personal division of work:
As I am very interested in special effects, the simulation part, I was responsible for the special effects (particle and volumetric effects), the design and sculpting of the body of Yog-Sothoth, and the compositing of the final shot.
1. Particles Effects Part & Composition :
The main particles:


Swirl particles:

2. Design of Yog-Sothoth:
In my conception and understanding, I wished to design a Yuggothoth that was not a traditional Cthulhu character, I wanted it to be more mysterious and elegant, to achieve this goal I made several versions of the form and different motion forms, not least with hair dynamics (blender), but finally I chose the idea of using cloud-like eyelids to animate the opening of the eyes to reveal the eyeballs, as it is more mysterious.
References:

First appearance at the lake:
Past visions:

The final vision:

Last act proper (particles emitted from the feet of the body):
