Genjuu Souseiki (aka Genjū Sōseiki / 幻獣創世紀, translated as “Mythical Beast Genesis” or “Genesis Phantom Beast”) is a cancelled RPG that was in development in 1990 by Nihon Bussan / Nichibutsu for the Famicom / NES. It seems that players would have took the role of a god, fighting with other gods to conquer more areas of the world, using the power of monsters that were able to evolve like in Pokemon. Only few screens, a video and some info can be found in a japanese website.
Thanks to Celine for the contribution!
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