For more info, it would be cancerous. A tumour in the brain, spreading to certain areas over time. I wasn't sure if a healer could heal something like that? Otherwise, if they can that would be sweet! And if they could even detect something like that?
The crack was more of an artistic idea, that I thought would be interesting to have for the character. The substance kind of taking the place of the damaged cells, healing it, and then leaving that crack like mark on the body.
Thanks for answering though, much appreciated!