Yes, my pleasure to help - because others have helped me.
Boot.img is not magic.
Inside your rom zip file is a special file called boot.img.
The phone needs that installed in a special way so that your phone boots up properly.
Normally, we want it just install automatically from TWRP.
But sometimes, the S-ON security feature on the phone prevents the installation - of just that one file.
So, how to fix it is simple.
We unzip the ViperOneM8 zip file on your PC.
Now is the tricky part (that you are waiting on me for) - the ViperOneM8 zip file is a
universal installer.
So, instead of just one boot.img file, it has many. That is what makes it a universal file.
We will choose the right one and extract it from the zip.
Then we will copy or move it to the same folder where you have fastboot installed. (Please tell me if you need help and do not have fastboot installed).
Then finally, we will make a fastboot flash boot command to complete the installation with S-ON.
Later, when it is all working, we can give advise for you to try the Sunshine s-off app.
When you S-OFF security status, you have to play this boot.img game.
TWRP will always install it correctly with S-OFF.
But - first we need to make your phone working.