Yesterday I got a pretty good idea of how to tank the flames. What I did was to kite it around in a 8 shape like shown on the screenshot. The red dot is the glaive and the yellow is the flame. The reason for kiting it like that, is that when you have to turn it around, it will never face the raid.
There is basicly 3 things the tank needs to be aware of:
- Stay out of the eye beams when Illidan is casting them. When the blue trails are on the ground just move through them fast. It's better to take a couple of ticks from them than to end up in an awkward position.
- Make sure the Flame is facing away from the raid.
- Don't move too far away from the glaive.
And one final thing to all dps'ers: Its really, really hard to kite, stay out of the flames and to do decent threat at the same time, so if you are getting close to the tank, just switch target and dps the other flame a bit.