WoWDB

Mr. Thuzad requires some patience when soloing, because he resets very easily. When you run in his room stand in the middle blue circle - it will turn green when you do. Then, wait. Don't attack the skeletons that come in, they die automatically, but do poke the abominations when they come in the green circle, and use an ability to quickly kill the banshees that come in the green circle (they will blow you out). Eventually, Kel will charge in. Carefully poke him a few times, then burn him down.

There is an achievement to be had here for quickly running around and killing 18-or-so abominations. Again, your biggest enemy is doing this and getting in the circle before he resets.