Dragon made improvement to last battle (10)

I believe the answer is:

armageddon

I'm a little stuck... Click here to teach me more about this clue!

'battle' is the definition.
(I know that Armageddon is a type of battle)

'dragon made improvement to last' is the wordplay.
'dragon made' anagrams to 'ARMAGEDDON'.
However, I'm not clear how this is indicated.

Can you help me to learn more?

(Other definitions for armageddon that I've seen before include "Terrible war" , "large-scale conflict" , "Catastrophic conflict" , "extremely destructive conflict" , "final battle" .)

I've seen this clue in The Daily Express.

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