Victoria, Ragnar Backend.
Ragnar is just a bot able to recognize spam. To remember stuff it has A persistant xmlrpc backend called Victoria.
Register Spammer
This works with the native Python3 already installed on your system. Just execute Python3 and type:
from xmlrpc.client import ServerProxy
victoria = ServerProxy("https://victoria.molodetz.nl/rpc")
victoria.register_spammer("[The Username]")
Now the user isn't able to post anymore. Only works with new users to prevent abuse.