We'll create fresh WordPress site with WP-DenyHost installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Based on a users IP address, WP-DenyHost will block a spammer if he already has been tagged as a spammer. Use it together with the Akismet plugin. Akismet tags the spammer, and WP-DenyHost prevents him from accessing you site.
If you have a CloudFlare account, the plugin can add spamers to CloudFlare Block list