ADB bricked android doesn't connect to pc
Well, you've just messed with the system partition, so there's nothing much to panic.. Here's a stock ROM for your phone:

http://www.needrom.com/category/bluboo/x2-bluebo/ (Choose the ROM for the SAME android version you had before bricking).

The good news is you won't need to lose your data. Everything will be safe.

Download SP Flash Tools, load the scatter file from this ROM, uncheck all the partitions except ANDROID (SYSTEM) as this is the only partition you need to rectify. Click on Download and connect your device. Your device will be unbricked without having to lose any data.