Fantastic Voyage: 01 Fern Scene - Test render

I want to try and create atmosphere within these shots and for the whole animation to have an atmospheric feel to it, with the first render i felt the fog was too thick so I turned it down for the second render whilst also altering the composition of the fern within the shot.

I want to create a feel like a big light source through a paper like they would traditionally to create shadow puppet animation and similarly in 'The Three Brothers' animation in harry potter, but Im not sure how to achieve this, I may have the main light source flicker almost like it is a candle that is lighting the whole scene as this will also go alongside the burnt landscape visuals. I will be using after effects to make ashes too arise around the landscape to help reinforce the burnt landscape.