This is really the first story I’ve read about any sort of afterlife and it’s really good. You described the transition to death with many details and I really get the sense of how it is to die. It’s pretty difficult to do that because dead men tell no tales. Ambika is also interesting because she is not your average looking angel and I like how you don’t give the full explanation right away.
The only thing that bothers me is that each chapter is rather short and there are too many ellipsis marks (which are supposed to be 3 dots each), but I'm just picky like that. Other than that, it’s pretty good.
KEEP!! By all means, keep this story. I love how you set it up. You've completely drawn the reader in and made them feel what the character is feeling. Great job! I DEFINITELY want to see more of this story, even if I'm the only one who reads it XP