Who’ll show climate turning endlessly severe? (8)
I believe the answer is:
doomster
'who'll' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'climate turning endlessly severe?' is the wordplay.
'climate' becomes 'mood' (synonyms).
'turning' shows that the letters should be reversed in order.
'endlessly' means to remove the last letter.
'severe?' becomes 'stern' (I've seen this in another clue).
'mood' backwards is 'doom'.
'stern' with its last letter removed is 'ster'.
'doom'+'ster'='DOOMSTER'
'show' is the link.
Can you help me to learn more?
(Other definitions for doomster that I've seen before include "In Ayr I used to say sentence" , "One predicting disaster" .)