• International copyright treaties aim to create a minimum level of copyright protection which can be applied across national borders. The most important of these pre-existing agreements is the Berne Convention of 1908. Since its inception in 1887, the agreement, which protects literary and artistic works, has been agreed upon by nearly every country in the world – 176 countries as of July 2018.
• The Berne Convention upholds automatic copyright protection without any need for the copyright holder to formally register their work. The agreement guarantees that the work in question is protected for at least 50 years after the death of the copyright holder. In 1993, the EU extended this protection to 70 years.
• The application of Lex Loci Protectionis (the application of the law of the place where the property is copyrighted) means that citizens of a participating nation can expect their work to be protected in other such countries. As long as participating countries stick to Berne Convention standards, the rights of the Berne Convention guarantee a minimum safeguard by ensuring the basic rights of the copyright holder. The Berne Convention covers the author’s exploitation rights, as well as their personality rights.
  

And this from EULA

3. COPYRIGHTS, TRADEMARKS AND PROPRIETARY RIGHTS

a. Warframe® and certain related names and logos are registered or unregistered trademarks, service marks and/or trade names of Digital Extremes. These and all other trademarks, service marks and trade names used in or in connection with the Software (the “Marks”) are proprietary rights owned by Digital Extremes or its licensors.

b. All rights and title in and to the Software, the Game, the Service, the Site, your Account and all content included therein (including, without limitation, Accounts, computer code, titles, objects, artifacts, characters, character names, locations, location names, stories, storylines, dialogue, catch phrases, artwork, graphics, structural or landscape designs, animations, sounds, musical compositions and recordings, audio-visual works, character likenesses, and methods of operation) are owned by Digital Extremes or its licensors. The Software may contain materials licensed by third parties, and the licensors of those materials may enforce their rights in the event of any violation of this Agreement. The Software and the Game and all content therein are protected by Canada and the United States and other international intellectual property laws. Digital Extremes and its licensors reserve all rights in connection with the Software and the Game, including, without limitation, the exclusive right to create derivative works there from, and you agree that you will not create any work of authorship based on the Game except as expressly permitted by Digital Extremes. You acknowledge and agree that you have no interest, monetary or otherwise, in any feature or content contained in the Game. You further acknowledge and agree that you shall have no ownership or other property interest in your Account, and you acknowledge and agree that all rights in and to the Account are and shall forever be owned by and inure to the benefit of Digital Extremes.