A diabolical fire felt to be one's eternal existence? (9)
I believe the answer is:
afterlife
'eternal existence?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'a diabolical fire felt to be one's' is the wordplay.
'a diabolical' indicates anagramming the letters.
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
'be one' becomes 'a' (a thing is one thing).
'fire'+'felt'='firefelt'
'firefelt' with letters rearranged gives 'fterlife'.
'fterlife' after 'a' is 'AFTERLIFE'.
Can you help me to learn more?
(Other definitions for afterlife that I've seen before include "Existence following death" , "Hoped-for future" , "Existence beyond death" , "Existence beyond the grave" , "Post-death existence" .)