Yeah that was the most irritating and worst mission. Build turrets middlw and around bases! If you see Ordos Deviator coming, make sure you take it out first or else you'll find yourself fighting with your own units. Mongosee are your best be against those b*****ds. Then build a few engineers transport them into APC, then get carryall to take the APC and then bring them to the abandon base. Capture the megacannon and sell it cause evern if you manage to catch it, it'll still attack you. Bring that base up to speed, mix freeman fedyrakin with those saudakar elite soldier and make your way to the worm's head. Shoot it and make sure you blow it up real good!