Upsets soldier consumed by what's passed on by ancestors - the forbearing kind (6)
I believe the answer is:
gentle
'kind' is the definition.
(I've seen this before)
'upsets soldier consumed by what's passed on' is the wordplay.
'upsets' says the letters should be written in reverse.
'soldier' becomes 'lt'.
'consumed by' means one lot of letters goes inside another.
'what's passed on' becomes 'gene' (I can't justify this - if you can you should give a lot more credence to this answer).
'lt' reversed gives 'tl'.
'tl' going into 'gene' is 'GENTLE'.
'by ancestors the forbearing' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for gentle that I've seen before include "Tender - maggot" , "Jane Eyre's kind person with a book? -- eternal greed (anag)" , "Kind - maggot" , "Mild, kind, tender" , "bait used by anglers" .)