I'm on the part after the poison dude and i walked through a door and there were to chests but a lot of guards so i would die. My guy said i need an invisbility potion. Im level 18 priest
At the back of the Emerald Temple there'll be a trader that sells them.
My tip on multiple guards, bait one or two then run away so not all of them go after you. I remember getting frustrated near the end when I'd run into two magic dudes and some warriors, but my strategy worked. Only the warriors would follow me and that wasn't too difficult, then I'd be able to heal then take out the magic guys.