Organic aura effects

I feel like we need more organic looking black or green aura effects. Most of the options for these color pallets seem to be of a synthetic theme . They look great, but I always struggle making match when trying to keep a darker occult or beast like theme with a character design, at least when I am stuck on these two color choices.

More often I end up hiding the effects or feel like I'm forced into adding blue/red to the design.

If any art team could pull it off, it would be you guys.

Cheers, SS IRL.