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