The evil adventurer that the MC killed for throwing the sheep girl into the hole.
His friends were all killed by the cyclops, and somebody dumped his body into the hole after MC killed him not far away from it.
And it just so happened to be when the cyclops was standing bellow the trash hole.
its a one in a billion chance occurrence which makes people call it a deus ex machina moment.
But he more or less got his revenge for his dead friends after his death.
I wouldn't even be mad if we later learn that it all happened because the dungeon itself / something that controls it wanted to help the MC out.
it would be more believable then it just randomly happening at this exact timing.
aint gonna lie, the whole vengance from beyond the grave is incredibly contrived/deus ex machina, but atleast, its not some redemption thing, it just sheer chance
not the best bullshit, but i can still belive it
Also, how fucking outleveled where they? that massive levelup is insane and the skills seem to finaly go into the practical outside fights category