Previous quick solution

Across: 1. Arms 8. Proponents 9. Fearsome 10. Ripe

12. Mirage 14. Oxygen 15. Miasma 17. Purser 18. Keen

19. Supplier 21. Relentless 22. Then.

Down: 2. Repetitive 3. Spur 4. Morose 5. Forego

6. Betrayer 7. Isle 11. Preference 13. Assented 16. Assets

17. Puppet 18. Kerb 20. Last.