Armor Class 14 (natural armor)
Hit Points 110 (13d10 + 39)
Speed fly 60 ft.
Skills Perception +8
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, grappled, paralyzed, petrified, poisoned, prone, restrained, stunned
Senses blindsight 360 ft. (blind beyond this radius), passive Perception 18
Languages —
Challenge 9
Magic Resistance. The fractine has advantage on saving throws against spells and other magical effects.
Scrying Focus. A spellcaster can use the fractine as a substitute focus when casting the scrying spell or similar magic, provided the spellcaster and the fractine are within 5 feet of each other.
Two-Dimensionality. The fractine can occupy another creature's space and vice versa. It can move through other creatures and objects as if they were difficult terrain, but it takes 5 (1d10) force damage if it ends its turn inside an object.
Unusual Nature. The fractine doesn't require air, drink, or sleep.
Extradimensional Touch. Melee Spell Attack: +5 to hit, reach 5 ft., one target. Hit: 24 (8d6) force damage.
Imprison. The fractine targets one creature of its size or smaller in its space. The target must succeed on a DC 16 Dexterity saving throw or be imprisoned in a demiplane. While the creature is imprisoned, a distorted image of it can be seen on the fractine's two-dimensional surface. The demiplane moves with the fractine, has indestructible and opaque walls, and is only as big as it needs to be to contain the target, which doesn't suffer from hunger or thirst while imprisoned. No other creature can enter the demiplane, and the fractine can't be harmed from within the demiplane. The fractine can imprison only one creature at a time and can release that creature as a bonus action. If the fractine is reduced to 0 hit points, any creature in the fractine's demiplane is released instantly. A released creature reappears in an unoccupied space as close to the fractine (or where it died) as possible. A creature can leave the demiplane on its own by using magic that enables planar travel, such as the plane shift spell.
Mirrored Damage. In response to being damaged by a creature it can see within 120 feet of itself, the fractine forces that creature to make a DC 16 Constitution saving throw. On a failed save, the creature takes 24 (8d6) force damage. On a successful save, the creature takes half as much damage.
Split. When a Large fractine that has at least 10 hit points remaining takes bludgeoning, piercing, slashing, or thunder damage from any source, it splits into two Medium fractines. The new fractines occupy the space formerly occupied by the original fractine, and each new fractine has hit points equal to half the original's, rounded down. If the original fractine had a creature trapped in its demiplane, that creature is released when the fractine splits, reappearing in an unoccupied space as close to the new fractines as possible.
MCV1SC, p. 7