X-gene

From Furinkazan: If you like +anima and are over 18, this manga is for you. X-gene is about a few chosen people, whose DNA contains genes from certain unique animals that can turn them into that animal and receive its attributes. What makes this game even more deadly is that they can kill and consume other X-genes?(as they are referred as in the manga) powers and use it for themselves. But they need to hurry, for only one can enter the ark.