In this past year, Vishnu cultivated and concocted diligently, but in addition to that, he did another thing on daily basis. That is to feed Fenrir Alchemy products. Even though the little guy has entered hibernation he can still place pills and elixirs in his mouth and it'd be swallowed. It is as if his body is accepting these nutrients.
He fed the little guy all sorts of products that are helpful for beasts and finally, after almost five months the guy woke up. And as it woke up it released a terrifying amount of energy. Even Vishnu's face became pale in horror. Fortunately, Arthur was there to suppress the energy. For a Moment the whole Elemental Heaven mountain entered into a frenzied state.