Question iris and body animation for character

hello

I was wondering how would I add animation to the character iris eye part ?
I have been thinking if I do the animation in blender first for example like fire physics simulation so the eyes have fire type of animation.

What would be the best way to do it and how I add the animation on the characters iris only, kind of bound to it when the character moves so the iris animation stays on the eye as well?

Also how I would avoid clipping when the character eye lid closes and opens so the animation don't clip through the eye lid?

One way I thought could be to round the animation to adapt the ball shape of the eye ball would this be the best way?

I have also thinking to add same idea to the body as well, but in the way that there is these slits on the body that has like glass type of material so you see through inside the character where the fire effect takes place to give the character like the idea of fire roaming inside. The body fire don't need to be specifis like in the eyes it can be super blurred giving just like bloom light outwards and very hazy look so you can't make out of the shape of the "fire" it self. Also lava like movement could work as well.


I'm not doing low poly game so the graphics quality must be AAA.
I'm also not doing huge game so my AAA game is very plausable since there is just couple of characters overall, but they are all on the high end of graphics at the moment. The character that I'm looking to add these effect is already done.


If you know how I would proceed with the ideas I much appreciate it thanks