Suldanessellar Overview - Baldur's Gate 2
Suldanessellar is the first map of Chapter 7 in Baldur's Gate 2. In order to reach this map you will first need to acquire the Rhynn Lanthorn from Bodhi's Lair during Chapter 6 and bring it to Elhan at the Underdark Exit map. After you have done this Elhan will meet you outside of the Suldanessellar entrance in the Forest of Tethir and open the door for you when you talk to him.
As you may already imagine, since this is an end game zone the enemies here will be quite difficult. Rakshasa, Iron Golem and Adamantite Golem enemies can only be damaged by +3 weapons or better. Additionally, Clay Golems can only be damaged with weapons that deal crushing damage.
Temple of Rillifane: To summon the Avatar of Rillifane you'll need to place the Golden Goblet of Life, Moonblade and Talisman of Rillifane inside the container in the center of this temple.
House of the Talisman: There are actually 2 buildings ontop of each other in this location - make sure to enter both! Inside of the downstairs building you'll find a glowing chest on the eastern side which asks for the correct order for all of the prompts. The correct order is Corellon, Rillifane, Water, Tree of Life and finally Suldanessellar. Answering all of these correctly will get you the Talisman of Rillifane; we'll need this item to summon the Avatar of Rillifane.
Demin's House: Inside this house you'll find Priestess Demin who will tell you how to summon the Avatar of Rillifane. You'll also find a Girdle of Stone Giant Strength on the ground after you defeat the enemies threatening Demin.
House of the Moon: Outside of this house you'll witness a scene with some Elves, one of which will drop Elven Chain Mail when they're defeated. Inside of the house there will be another scene, this Elf will also drop Elven Chain Mail when defeated. Additionally you'll find the Moonblade item which we need for summoning the Avatar of Rillifane. Boots of Elvenkind can be found in a container in the house too.
Harpist's House: You will find a Stone Harp inside of this building, you'll need the Harp when you're inside of the Elven Palace to open the route to the Tree of Life.
Forest Clearing: This clearing is home of a black dragon named Nizidramanii'yt. You have 2 ways of dealing with this dragon, you can either give him every piece of equipment and gold you have ($%^& that) or you can kill him. A neat trick is you can drop all your items on the ground so that you don't lose anything when you "give him everything" but this option is still not recommended. Fighting him isn't as hard as you may think, he's a lot easier than the other dragons. If you need help with strategies for getting better at this game check out my BG2 Beginner's Guide for more info. Defeating this dragon will net you the Golden Goblet of Life which you need to summon the Avatar of Rillifane.