Pit of Blood

Hello, i killed Oyo the Shaman because i could not be bothered with his stupid quest at the time. It was an unwise decision as it seems that i am now unable to go down into the Pit of Blood and kill the Troll or whatever hellish creature dwells that place. Are there any ways to go past the magic gate right now?

No, but that pit is optional - there's no other quest connected with that. You can hunt many of the same Cyclops south of Phryn