You got the good for a good logline here, but it's way too long.

I'd pare it down to: "When a collection of disgraced 'adventures' wind up in a magical world on the brink, they fight for who has the right to power."

Very good!

I agree with you MIchael, that it's a little longer than your standard logline, but it's a complex and ambitious show that's really about two things - how broken people come back from spectacular failure, and what happens to people when more and more power is concentrated into fewer and fewer hands. And that's before I even get into how Dungeoneers genre hops in a way that isn't forced but is intrinsic to the plot of the three-season show.