the lazy fuck wants to get paid 20-30% of the future sales of the project
		
		
	 
Sorry for insisting on these aspects. But I also work as a content creator and I'm very sensitive about copyright issues (although I'm in a pirate forum... it's one thing to know the law and another to follow it, hehehe, but, of course, I don't consider that it is "a right" to pirate content, I am aware that it is wrong)
You are basically accusing Javier of simply enforcing his rights. Certainly he could have kindly given away all the content he created without asking for anything in return, but hey, almost all of us like to get paid for our work, right?. Both options - giving away his work or asking for money in exchange for it - are perfectly respectable, I think.
If you still have doubts about how this copyright is going, here is a summary:
Ownership
For literary, dramatic, musical or artistic works, the author or creator of the work is the first owner of any copyright in it.
However, if you made the work as an employee, your employer is usually the copyright owner, unless you have agreed otherwise. In these cases contractual terms are often the actual rules governing the ownership of a work, so you should carefully check all clauses to understand who owns the several exclusive rights involved. 
If you create a work with other people, this usually results in joint ownership of the copyright. If someone wants to use this work, they need the permission of all the copyright holders, not just one.  
 
Economic rights
The copyright owner has the exclusive right to copy the work, issue copies of the work to the public, rent or lend the work to the public, perform, show or play the work in public, communicate the work to the public, edit or adapt the work, sell or license the copyright for use by others.