Vaarh's irritation with Adam's actions was understandable. He knew that for the Phantoms, monster energy was a destructive thing.
Sure, even ordinary humans could eat monster meat, not to mention the Phantoms, but these two situations were different.
When an ordinary human or a Phantom ate monster meat, it was at least several hours after the monster had died, or even several days. Thus, there was no active energy left in the monster meat.
Moreover, at that moment, a Phantom was usually at the peak of his powers, so a small amount of foreign energy could not harm him, but it could not make him stronger either, as happened with Vaarh.
In Adam's situation, it was like drinking deadly poison.
He was exhausted and almost on the verge of death. The black wolf's heart was still beating in his hand, it was as fresh and full of energy as possible.
Thus, as soon as he ate the monster's heart, all its energy went into his inner space, moving towards his Evolution Tree.
