In this kala of Flash-ing,  Rooting and Custom Rom's no one can say when and what will go wrong and you might left with a useless brick in your hand. But relax we can take a backup or flash back stock firmware with SP Tool to fix our device. But what if your device manufacturer don't even care to provide the stock firmware to restore. Don't worry Some awesome developers are keeping our back with there developed awesome tools one of it is MTK Droid Tool. Well i am not going to explain what it is and how it works you can read about it here.
Here i am just going to show how can you take a backup of your stock rom with MTK Droid Tools.


Requirements:

Any MTK android device running a Stock ROM. (Note: if your device was rooted, then you'll get a rooted Stock ROM, otherwise if your device does not have root access, you'll get unrooted Stock ROM):

MT6595, MT6592, MT6589, MT6582, MT6577, MT6575, MT6572, or any MT65xx

MTK USB Drivers - Download it here (credits to the developer of this tool)
MTK Droid Root and Tools - Get it here
SP Flash Tool - Get it here (download the recommended or latest version)
Device Drivers

ADB Drivers : - Get it here
pdaNET : - Get It here
MTK VCOM Drivers :- Get it here

Instructions:

1.  Enable USB debugging on the good MTK phone (Settings > Developer > Tick USB Debugging) then connect it to PC. If you don't find Developer under Settings then go to Settings > About > Keep taping Build Number
2.  Install PdaNet on the PC with the USB debugging enabled working MTK phone still connected (Select Other from the list of devices during installation)
3.  At the end of PdaNet installation, you should get a "drivers successfully installed" message
4.  Exit PdaNet in system tray (bottom right corner of PC)
5.  From your computer, Open MTK Droid Tools.exe, run it as administrator. Wait for your device to be detected since you have installed the USB drivers. You will notice that color on the lower-left corner of the tool will turn cyan-blue.

6.  MTK droid tools should detect and display the phones details by the left along with a yellow box at the bottom.


7.  If your device is rooted and still it shows this message just chick Root button. A progress kafe should load at the bottom shortly after which the yellow box should become green.
8. Click on the root,backup,recovery tab at the top.
9.  Click Backup (MTK should keep writing some things by the right hand side during backup) and wait till backup is complete. If you get a prompt to pack backup, select No.


10.  Once backup is complete, don't close MTK droid tools.
11. Go to the MTK droid tools folder > Backups > Folder named after the phone's model e.g mmx_m3_backup.... and take note of this folder as the 'Backup folder' because we'll be referring to it soon.
12.  Go back to MTK droid tools and click 'To prepare blocks for Flash Tool'.

13.  A window will open, in this window, navigate to the Backup folder (mentioned above) and select the md5 file.
14.  MTK will start copying some items (check the right hand side) so wait till copying is complete.
15.  Once copying is complete, open the Backup folder and you should see a folder named "!Files to flash".
16.  The !files to flash folder contains the files needed to use Sp Flash tool.
17.  Both the !files to flash folder and the x_backup folder (which contains the !files to flash folder) are your phone's MTK backup.
18.  If you need an MTK Droid tools backup of userdata and cache then use MTK Droid Tools version 2.3.0 or do a read back using Sp flash tool (see  here)

How To Restore the Stock ROM of your MTK device?

Just follow this guide here and use the above backup to flash. 

Done! You have successfully restored the stock ROM.

See also:

How to Take Backup Of Stock Rom With SP Flast Tools