I need detailed instruction on how to recover a ZTE z828 lt from soft brick caused by Kingo root! I need detailed instruction on how to recover a ZTE z828tl  from soft brick caused by Kingo root!  

I bought this “simple mobile ZTE Midnight pro LTE” off eBay, and simple won't unlock it, so I can use it with anyone else, so I was playing with KingoRoot trying to root it, the computer version said root complete please donate, the phone rebooted into boot loop, I can access the stock recovery screen, but can't do a factory reset, and I can get to ftn!!!  

Please help, I am a newbie to android, cell phones, but have messed with tablets for years, and usually can get a factory ROM restore for flashing, but this time I've searched all over without any luck..

Thanks.
I did the same thing as you and ended up in a boot loop but then I wiped the cache when I entered recovery And then restarted phone, let it boot up for a while then it restarted on its own.  I immediately did the button combo for recovery again and then did a factory reset.  I downloaded SuperSU and was still rooted. Hope this works for you.  Please let us know.