Shadowy Apparition: Whenever it doesn't move, doesn't take any actions for a turn and didn't get hit by any source last turn, Zaraxus becomes invisible.

Dimensional Rift: Whenever Zaraxus reduces a creature to 0 hit points on it's turn it can use it's bonus action to teleport anywhere within sight.

Mind Slash. Unarmed  melee Attack: +5 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) psychic damage.

Mind Probe. Ranged Attack: +5 to hit, range 45ft, one target. Zaraxus enters the mind of the target with one of it's shadowy tentacles (barring a Wis 16 Saving throw) and makes a psychic connection. If Zaraxus is damaged while linked, the probed target takes 1d6 Psychic Damage.

The Mind Probed creature cannot move, but can take all other actions as normal. If the player takes damage from a source other than Mind Probe, or is moved from the space they occupy, the link is severed. If the tentacle is attacked directly, the link is also severed, but the Probed creature still takes damage. This effect cannot be blocked or resisted by any other means than the effect of a powerful magic item or the creature not having a brain to begin with.

Pierce the mind: Range Attack on a Tethered Creature: +5 to hit, reach 40 ft., one target. Hit: 16 (3d6) piercing damage +1d6 Psychic Damage

Passive Actions

Suck the Wits. At the start of it's turn, if any creature is Tethered, Zaraxus will start to consume the minds of all Tethered Creatures dealing 1d6+3 necrotic damage to each target and restoring the same value as the 1d6 hit points to itself per tethered target.

Tether. Connect with any creatures within 10 yards (Wis. Saving throw DC 15). This connection lasts until the creature dies or is further than 40 feet from Zaraxus.

Blinding shadow: When an creature within 5 ft. misses Zaraxus with an attack, they gain disadvantage on the next saving throw they make until the end of their next turn.