If you root your phone with Kingroot,the user will be Kinguser or Kingroot by itself.
Do you want a Supersu instead of Kingroot?
This will help.
Requirements:
SuperSuMe
https://sites.google.com/site/androidxdacom/file/supersu-me-v6.7.apk?attredirects=0
Install the apk
Launch
Grant it with...