Why on earth would you try to help DDOS'ers? I think you should really take a step back here and reevaluate what drives you here and what impact you have on other people.
edit : oh and what the hell, name and shame https://www.reversecanada.com/ (and they have variants for other countries)
A court ruling exempted Cloudflare from its users infringements of copyright making things easy for them.
In practice however, when you peel off Cloudflare you'll be stumped anyways as the DMCA request will be plainly ignored by those "bulletproof" hosts, so I don't think that knowing the real IP would change your chances, and if you're formally filing a case why just not subpoena Cloudflare?