|Titles||The World Thunder|
|Home||Mhar Massif, Varisia|
|Areas of Concern|| Caverns|
|Domains||Chaos, Destruction, Earth, Fire|
|Subdomains||Ash, Catastrophe, Caves, Smoke|
|Favored Weapon||Heavy pick|
|Symbol||Shattered triangular rune|
|Sacred Colors||Black, orange|
Source: Spires of Xin-Shalast, pg(s). 52
(chaotic, evil, Great Old One)
Source: Rise of New Thassilon, pg(s). 86
Aeons ago, a unique planar rift caused the essence of the Plane of Fire and Plane of Earth to fuse together on the edge of the Material Plane, coalescing into Mhar. Seeking to alleviate its pain but unable to leave the Material Plane, it instead chose to travel the universe and settled on hot, molten young planets. Mhar rested in the core of such planets for some time, but eventually even the primordial heat would prove insufficient to keep it sleeping, at which point it awakened and destroyed the planet. This cycle repeated numerous times until Mhar found a way to come to the Plane of Fire, but its power was insufficient to do so, so it burrowed into the core of a young Golarion from Mhar's Fossa in Leng, taking advantage of the Storval Thinning, where the veil between the planes is thin, and waited to grow.
When Sarenrae opened a corner of the Material Plane to create the Dead Vault, she also temporarily killed Mhar and put it out of its misery, but such an act is insufficient to permanently destroy a Great Old One. As Mhar eventually awakened again, it found itself trapped under Golarion's crust and went insane. Its psychic convulsions rebounded between itself and Golarion's surface, intensifying its madness and creating the Kodar Mountains on the surface. Some scholars mistakenly believe this to be the sign that Mhar failed to be born, while its cultists know that its gestation is unfinished and takes uncounted ages to complete. Mhar's resting place, dubbed Mhar Massif, was later chosen by Runelord Karzoug as the site of Xin-Shalast, capital of his realm Shalast.
Mhar seeks to erupt into Golarion's crust and cover the entire world with magma, which it then uses as a focus to open a portal to the Plane of Fire and consume the entire Material Plane in lava, so it could finally find peace.
In 4708 AR, under orders from an unknown patron from Kadath, several denizens of Leng sojourned to the Material Plane in an attempt to awaken Mhar using a time-distorting artifact called the Leng Device. Their plans were thwarted by the same group of adventurers that killed Karzoug. Had Mhar been awakened, it would have spelled doom for Golarion.
Worshippers congregate near volcanic areas and seismically active rifts, aiming to spark geological events. Through magic and living sacrifice they hope to force open the correct vent and awaken Mhar. They believe that Mhar's birth can be predicted by a sudden increase in earthquakes and volcanism, and when it finally happens, Mhar will cover northern Avistan, and eventually Golarion itself, in fire and ash.
- Original Source: Greg A. Vaughan, Spires of Xin-Shalast, 2008; James Jacobs. (2016). The Elder Mythos. In Search of Sanity, p. 73. Paizo Inc. ISBN 978-1-60125-882-3
- James Jacobs. (October 28, 2010). Old Ones Cult, Paizo Messageboards.
- Greg A. Vaughan. (2008). Spires of Xin-Shalast. Spires of Xin-Shalast, p. 52. Paizo Publishing, LLC. ISBN 978-1-60125-041-4
- John Compton, Andrew D. Geels, Lyz Liddell, Luis Loza, and David Schwartz. (2019). Bestiary. Rise of New Thassilon, p. 87. Paizo Inc. ISBN 978-1-64078-106-1
- James Jacobs. (2016). The Elder Mythos. In Search of Sanity, p. 68. Paizo Inc. ISBN 978-1-60125-882-3
- Greg A. Vaughan. (2008). Spires of Xin-Shalast. Spires of Xin-Shalast, p. 61. Paizo Publishing, LLC. ISBN 978-1-60125-041-4
- Colin McComb. (2011). Faiths of Corruption, p. 20. Paizo Publishing, LLC. ISBN 978-1-60125-375-0
- James Jacobs. (2011). Cults of the Dark Tapestry. Wake of the Watcher, p. 65. Paizo Publishing, LLC. ISBN 978-1-60125-311-8