So is your problem:

1) the fact that he tried what he did, or

2) the fact that the virus regressed?

We explained 1, and you know all about a certain other parasite that needs to reach the brain in due time before it has to settle down. Ryll suggested the gem had something to do with it. The asphyxiation may have too.

For all we know, perhaps he is a Kagane with a human head. I really don't think they're going to skip on an explanation for this.

edit: beat you again Ryll.