On the Spanish Wiki page, we have this quote about the Daemon Lord Doombreed, attributed to Richter Kless:
Un antiguo Príncipe de Khorne llamado Doombreed empujará a los mejores y más puros de la Humanidad hasta el borde de la destrucción. Pocos caerán, en comparación con otras invasiones, pero el coste será realmente alto. Su guerra será nada menos que una declaración de guerra contra los Astartes, los más firmes de todos los enemigos del Caos, y él será derrotado. Pero me lamento por los Halcones de Guerra y los Veneradores, pues serán perdidos.
Or, in English:
An ancient Prince of Khorne named Doombreed will push the best and purest of Humanity to the brink of destruction. Few will fall, compared to other invasions, but the cost will be truly high. His war will be nothing less than a declaration of war against the Astartes, the most firm of the enemies of Chaos, and he will be defeated. But I weep for the Hawks of War and the Venerators, for they will be lost.
I can't find this quote in Spanish or English anywhere except that one page. When I check my copy of Liber Chaotica, which is where it would logically appear if Kless said it, it's not there. On the other hand, it seems like something that might have appeared there, possibly in a later printing or hidden in the almost unreadable notes in the margins.
What is the official source of this quote, if any?