Once the crack to hell was closed, Aria took care of the demons who arrived in the fifth wave. Victoria, the guild members, and the other players helped in killing all the demons.
However, even the demons from the first wave had spread across the entire realm, and it was impossible to defeat them all while staying in the capital.
But, only the demons from the first wave spread all over the first realm, since Aurora had annihilated the second wave before it could scatter around. And Zach had taken care of the third wave.
In the fourth wave, the demons were too scared to do anything, thus they didn't scatter. And the fifth wave was the same.
The demons from the first wave weren't strong, but they weren't weak either.
However, a player with level 20 or above could defeat them with minimal effort.