Assume:
The Principle of Non-Contradiction (not “A and not A”)
Proof:
If a being possesses all power, then it must possess the power to destroy itself, because if it does not possess the power to destroy itself, then it does not possess all power.
Consequently, if a being possesses all power, then it is destructible.
Likewise, if a being possesses all power, then it must possess the power to resist being destroyed by any power (even its own), because if it does not have the power to resist being destroyed by any power, then it does not possess all power.
Consequently, if a being possesses all power, then it is indestructible.
Thus, if a being possesses all power, then it is both destructible and indestructible in the same way, at the same time.
But, a being cannot be and not be in the same way at the same time (PNC).
Therefore, there is no being that possesses all power.