Just two beasts and one player against hundreds of thousands of players and an NPC army; what could the result possibly be?
It's total annihilation. Even the city was razed to the ground.
Actually, Wil never intended to destroy everything.
Wil knows the requirements to win the war. Hence, he never paid attention to any player.
Instead, he focused on just killing the generals and then the king while leaving the remaining to Leon, Rexy, and the lava golem.
However, after killing the king and the other generals, a few generals escaped the palace for their lives under the advice of 'Wisdom Queen' and the other players.
To find them, Wil had to destroy everything in his path, thereby annihilating millions of NPC citizens and their homes in the process.
The battle lasted for five whole hours in the night, and by the time the world gets to take notice of it, the capital city of Everton has disappeared from existence.