Qliphoth

The Qliphoth is the Tree of Death, which once it bears fruit, gives The Ultimate Power to whoever claims it, making him Demon King of the demonic legions of hell. It is a giant tree that only grows in Hell.

Season 2
It is what Todd Howard was seeking, to bend reality to his will.

Having obtained The Fruit already, Todd has ascended beyond human, and even demon, comprehension. His powers are unimaginable and his will can change reality itself. Soon our reality will become the Howard Reality.

Season 3
Todd Howard wasn't able to fully control the power granted by the fruit, which is what caused small reality abnormalities. When Todd died, all that power was released, making reality really unstable. It was at this point that Chris-chan used The Focusing Stone to seize control and force the Dimensional Merge.