alexis kerib
The main antagonist from SSSS.Gridman. He is a being that came from the void dimension, due to his origin, he is completely immune against all kinds of attack.
Alexis "offered" Shinjou Akane a helping hand "managing" the world she created via using his power to transform Akane's sculpture into kaijuu.
His goal is collecting negative energy from Akane as well as the destruction of the cyber dimension.