The Chosen Ones

OK to answer your questions, Tazefda, the barrier blocking the south west and the empty area you see next to the lake are all part of the epic boss quest.

First get a true sight item (that dust of appearance thing from the Troll shop for example) and travel to Rot'Afor. If you go to the burning town, you can go south across a bridge and into the castle itself. Stand on the south battlement and you will get a cutscene.

Now look for Tazefda, he will appear in a random spot out of about 5 possible places. You can either run around and find him or ask someone with an unprotected.map to tell you the spots.

Once you find him click on all the wisps fast. If you do it correctly he will say "too slow" and teleport to the top of the map. You have to go there and click all the wisps again before they disappear.

Then travel to that area next to the lake to start the Tazefda fight with Galeoth.

After beating him the barrier south west will disappear and you can access the Epic Boss. A very interesting fight, not too dangerous.

hamza