Size/Type: Large Construct (Psionic)
Hit Dice: 10d10+40 (95 hp)
Initiative: +0
Speed: 0 ft.
Armor Class: 34 (-1 size, +25 natural), touch 9, flatfooted 34
Base Attack/Grapple: +7/–
Attack: –
Full Attack: –
Space/Reach: 10 ft./10 ft.
Special Attacks: Mentalith nova, crystallize flesh
Special Qualities: Construct traits, blindsight 50 ft., DR 10/deep crystal, PR 20, telepathy 100 ft., levitate
Saves: Fort +9, Ref +9, Will +12
Abilities: Str –, Dex –, Con –, Int 20, Wis 20, Cha 20
Skills: Bluff +12, Concentration +18, Diplomacy +18, Intimidate +11, Knowledge (Psionics) +18, Knowledge (The Planes) +18, Psicraft +18, Sense Motive +18
Feats: Ability Focus (Crystalize Flesh), Improved ToughnessCW, Great Fortitude, Lightning Reflexes
Environment: Any
Organization: Solitary, pair, or henge (3-6)
Challenge Rating: 7
Treasure: None
Alignment: As creator
Advancement: 11-16 HD (Large), 17-25 HD (Huge), 26-32 HD (Gargantuan)
Level Adjustment: –

Mentaliths are psionic guardian constructs first created by an ancient race of psions, often said to be the forerunners of the two Gith races. Some modern psions have also learned the secrets of creating the constructs. Though immobile, Mentaliths possess a strong, if alien intellect. Though not mindless, they will obey any order given to them by their creator, and prove fairly loyal even to those who are not. Mentaliths are 15 ft. high monoliths of stone weighing three tons, with thick veins of deep crystal running through them. When they use their telepathy, these veins pulse with radiant indigo light.

Mentalith Nova (Ps)
As a standard action, a Mentalith can reform itself into 10 ft. radius circle of smaller standing stones. While in this form, it cannot be attacked, damaged, or otherwise impaired. As a standard action, it may extend its radius a further 10 ft., to a maximum diameter of 100 ft. Each round, all creatures, all creatures within the circle, up to a height of 20 ft., take 5d10 points of damage, as psionic energy courses throughout the circle. After one minute, the Mentalith automatically reverts to its normal form, and it must wait 1d4 minutes before it can use this ability again. In addition, if a dispel psionics power is manifested on the Mentalith while in this form, if the manifester makes a DC 20 manifester level check, the Mentalith automatically reverts to its normal form and takes 5d6 points of damage. This is a mind-affecting ability.

Crystallize Flesh (Ps)
Whenever a creature touches a Mentalith in its natural form, the creature must make a DC 22 Fortitude save or be turned to crystal as the crystallize power, manifester level 10th. The save is Charisma based. The crystallized beings is fused to the Mentalith, requiring a DC 25 Strength check to remove it. Even if removed, the crystal being is inevitably damaged, causing it to take 5d6 points of damage when–and if–it is restored. A Mentalith may suppress or resume this ability as a free action. If the crystalized being is not removed from the Mentalith within 1d10 days, it is absorbed into the Mentalith, causing it to permanently gain a single HD.

Levitate (Ps)
A Mentalith may use levitatation to move...very...very...slowly. It may not levitate straight up into the air, and levitating 5 ft. takes the Mentalith 3 months.

The body of a Mentalith is carved from a single piece of stone, which must bear veins of deep crystal, worth 2,500 gp. Creating the body requires a DC 18 Craft (Stoneworking) check. In addition to the prerequisites listed below, creating a Mentalith requires certain ancient psionic construct making techniques, which can be learned in one of three ways. A DC 35 Knowledge (Psionics) check is sufficient to learn the techniques, as is any spell or power of 6th level or above that reveals information, such as legend lore or hypercognition. Finally, spending a week studying the a Mentalith or the remains of a Mentalith, and making a DC 25 Psicraft check, allows the techniques to be learned.

ML 13th. Craft Psionic Construct, crystallize, psionic levitate, ultrablast. Cost 12,500 gp + 800 xp. Price 20,000 gp.