Final boss of the game and its unbeatable unlike evilen and Dragoite. Noui describe 8tive as a object with no emotions and can revive. Its unclear why he is the strongest but both Dragoite and evilen dont acknowledge his power to be strong. 8tive ultra formation is powerful to knock Lily into subconscious level however it needs both evilen and Dragoite to be defeated.
Its possible that 8tive has powers to create monsters however that has not been shown yet. The thing is immune to death and can revive when there is a way to destroy it. 8tive ultra formation is unbeatable and sealing it is the best way to win.
In real life this is called the Mystic Mountain from the Carina Nebula.