Adrian vanished from Olympus and did not even know the great chaos that he has created for them. All he can focus on is his body being corroded by Void Energy. His current body might be somewhat resistant to Void Energy but it does not mean he is immune to it. If he did not keep a poker face earlier then the Olympian Gods would have known something was wrong with him.
Adrian's right arm could be seen tainted with Void Energy as if it is eating it alive. This is also the reason why he kept it behind him and used his left hand to snap his fingers earlier. Fortunately for Adrian, he was given a gift by the Tree of Life and Death. As soon as he felt the troublesome energy of the void encroaching on his body, he placed the leaf of the Tree of Life and Death on his mouth and chewed.
