Accustomed to the dark tunnels of the underdark, you can see in dark and dim light easier. You gain darkvision out to 120 ft. You can see in dim light as if it were bright light, and you can see in darkness as if it were dim light. You can't see colors in darkness, just shades of gray.

Your innate spellcasting ability is psionics. At 6th level you can cast Detect thoughts at will. Starting at 10th level, you can also cast levitate on yourself at will. At 15th level you can cast dominate monster once a day. Intelligence is your spellcasting ability for these spells.

Your tentacles are natural weapons. Intelligence is your attack bonus and damage bonus, and the reach is 5 ft. On a hit, you deal 1d6 physic damage. This damage increases to 2d6 at level 6, 3d6 at level 11, and 4d6 at level 16. If you kill an opponent with this attack, you can extract their brain. You get temporary hit points equal to the targets challenge rating ( or level if it is using character levels) + your proficiency modifier. You can only benefit from this once per long rest. 

You can use your action to emit a psionic blast in a 60-foot radius around you dealing 1d8 psychic damage. When you use your mind blast, each creature in the area of the blast must make a Intelligence saving throw. The DC for this saving throw equals 8 + your Intelligence modifier + your proficiency bonus. A creature takes 1d8 damage on a failed save, and half as much damage on a successful one.  The damage increases to 2d8 at 6th level, 3d8 at 11th level, and 4d8 at 16th level. You can only use this once per long rest.