Hi Dark Pony
Have you considered a dark-mirror style tattoo.
This works on taking the images that you already have and copying them but in a much darker theme.
For example where you have the angel you could have a laughing demon tearing through a biohazard (or flag of choice) which has been set on flames.
The eagle could be a ghould bird or skeletal effect with the lamb slaughtered upon the floor with the lion ganwing on shreds of meat.
If not to your taste I am happy to put up more ideas.
Take care
Matthew