I am driving myself crazy with this dilemna I have finished the first three levels of Watcher's Keep and gotten the scepter gem from the cambion at the end of level 3 but no matter how many times I attempt to go through the last portal it continues to say something to the nature of "you do not have the item you need to go through." What I am wondering is this a bug, or am I just missing something. Thanks.
You need the Scepter and three gems. One from the Cambion. You get one each of the other 2 from the leaders of the waring tribes of Demons/devils. when you have all 3 and the sceptor on one person it will form the Sceptor of Radiance which will allow passage through the portal.
Yup, you need those gems and to get them just follow the instructions on the mad dudes manual. Thats how you got the first gem from the warring tribe 1. Now retrace your steps and go the same way, there should be another tribe there.