A desolate plane of heat and desolation.

You hurry through a red rift into a barren world of gray and black stone. There is no life anywhere in sight. The sky here is only a blanket of dark smoke. Deep fissures in the ground provide the only source of light and heat. They glow with burbling magma and spurt forth geysers of molten rock. - Gate of Brizoor Waal (RPA-ADVF)

• Dorgren

The Red Pearl is revealed to be the seed of a tree, the bark of which is raw durgolium, when planted in Nebblis;

It seems you have planted a seed in this plane, and it quickly takes root. A white-silver tree sprouts rapidly from the red sand. It grows thick and spreads its branches overhead while its gnarled roots crack the stone ground, creating fissures of sand. Into these fissures, the tree drops its acorns, and new sprouts spring up all around you. Before long, you stand in a forest of white-silver trees. Soon, the whole plane will be filled with them. You inspect their bark more closely and find that the trees are made of unrefined durgolium. - Gate of Brizoor Waal (RPA-ADVF)

Halfling Taron, atop a megapede, as the King's Guard, Giant Troll Urka for the Dragul, and Human Zerith of the Starlit Door all battle on a plain in Nebblis, Plane of Flame, at the final battle of Brizoor Waal:

Depending on which faction you side with, you will join the fray with their representative:

If you defeat the opposition and are favored by the character, they will greet you warmly. You claim the site, and find a red rune. If you defeat the opposition and are disfavored by the character, you will claim the site, finding a red rune. If you fall to the opposition, you stumble through a rift back to Elsifor's Tent at Brizoor Waal in defeat.