The Entity is the biggest enemy to FireWater and the Cosmic Savior, and they are the essence of what is evil and what is unknown. The Entity was created by Calamity. The Entity is a god-like power, that can easily destroy planets, stars and very rarely galaxies.
The Entity was created one yoctosecond after a specific universe was created. They immediately started attempting to destroy the universe it was in. FireWater was created by the Cosmic Savior to destroy the Entity.
Fights I and II
The Entity fought FireWater, and instantaneously won the fight against him. He continued to keep destroying the Universe, until FireWater escaped from them and had attempted a rematch. The power of the two when FireWater was enraged were almost equal, but the Entity was still slightly more powerful. However, this difference was very small, so they both fell, and both retreated to regenerate for later.
Fights III and IV
FireWater and the Entity fought again after one billion years of regeneration. The fight came close, but the Entity won again. To prevent fighting in the future, the Entity gave FireWater another chance to live, but he had to be corrupted for one million years and become his minion. He accepted, granting him more power than he ever had before. A friend of FireWater came to release him after a million years of being with the Entity. The friend was not going to win, but he was still let go, as the Entity would need to spend time regenerating.
Entity vs. FireWater
They both have only fought three times in the life of the universe they lived in. They fight once every 1 quadrillion years. The Entity has a 85.5% chance of wining a fight against FireWater if he is not enraged or determined to fight more than he normally would.
It is unknown exactly what the Entity is doing in modern time. It is likely that they are continuing to regenerate from battle, and destroying more than ever before. It is definite that the Entity wants to get revenge onto anyone who has wronged him, specifically FireWater.