hard brick? [asus zenfone 5 - lollipop]
The BEST way to unbrick an Android device is to use Odin. This exe program has saved many android users from having to buy another phone. Although I am not a pro with Odin, try looking up on Google about how to flash with Odin. Odin supports both Windows and MAC but windows is better. 

Did you ever make a backup of your ROM? Unless you didn't have a custom recovery, making a Nandroid backup is extremely important. 

If your device is hard-bricked with no backup, then you will need to download your original STOCK ROM (which can be found on the internet), and flash it through odin.

Also you will need a PIT file for your phone. PIT files tell Odin where to correctly place the files when flashing.

You can obtain the correct PIT file by looking up your phone model and then add "PIT file" along with the model.

I hope this helps!