how do you get these guys to apear?
do i get to fight them?
if so then can i have tips on how to beat them?

Read a certain tombstone in Nashkel 3 times and they'll appear. They are healed by fire and explode when they die (and of course healing their comrades). To make matters worse they are only worth 100 xp. You can also find a few in Durlags tower.

Explained it to him in the chatroom, but here goes again if anyone else wants the info. It's from out BG Encyclopaedia btw:

Daer Ragh - This mage will jump out from the graveyard he's hiding in in Nashkel if you click on his grave. He summons a bunch of phoenix guards - see "Phoenix Guards" - and he is not killable. Well he is, but he comes back again if you click on the grave again. Killing him gives you no exp.