HELP!

At the end of the movie, Yoki / Gingko walked into the silver light above the pond and disappeared.  Did this mean that he turned into a Tokoyami (Darkness) mushi in the end?

I haven't read the manga and i don't seem to find the answer when i search for it.  

Any clarification from a knowledgeable fan will be much appreciated.  Thanks in advance for your clarification and/or interpretation of the ending.