Don't let me waste time...
1.Stock boot.img for your phone model (its best its for your Build Number / Variant ) . You can extract from the stock rom / firmware of your device OR backup from your device using a box e.g Miracle box, CM2, etc
2.Download Latest Magisk Manager
Steps on how to root an Elephone P8 Max using Magisk Manager and patched boot.img
Step 1: Patching the stock boot.img
1.Install MagiskManager apk on your android device
2.Copy the stock boot.img of your device to your phone's internal storage or SD card
3.Launch Magisk Manager app
4.If prompted to install Magisk, select NO THANKS
5.If you are using a samsung device and wish to flash using Odin, then select Options > Settings > Update Settings > Patched Boot Output Format > img.tar )
6.Select Install > Install > Patch Boot Image File >
7.Navigate to the location of the stock boot.img you copied earlier on, then Select it
8.Magisk Manager should begin downloading the magisk zip file used for patching
9.Once download is complete, MagiskManager will automatically patch the boot file and store it under SDcard/MagiskManager/patched_boot.img[.tar]
Step 2: Flashing the patched boot.img
You have a variety of options to flash the patched boot.img depending on you
1. For Sp Flashtool copy the patched boot.img with mt6755 scatter file and make sure to rename patched boot.img to boot.img before flashing
2.For fastboot copy the patched boot.img to your fastboot folder and press shift right click on a free space in the fastboot folder, you would see open command here. Click on it and boot your Elephone P8 Max to fastboot with power+volume up and use volume down to select fastboot and connect your Elephone P8 Max. Your PC type fastboot devices to check if the system as seen it. Now type fastboot flash boot patched_boot.img
You are done.
3.For miracle box rename the file from .img to .bin before flash.
In case you lazy..
I have the patched_boot.img here
Enjoy..use root checker to confirm
Anyone who can support for custom recovery