Zaith'isk

A zaith'isk is a partly organic, partly mechanical Githyanki device that purportedly purifies a Mind Flayer Tadpole from an infected victim. One can be found in the Infirmary of Crèche Y'llek.

The Zaith'isk in Crèche Y'llek

Involvement

When you first talk to Ghustil Stornugoss, the resident doctor, selecting "I'd prefer Lae'zel to speak on my behalf" gives you  +1.

If Lae'zel is an active party member, the player character will gain  +5 and she will insist on using the machine first. If selecting "Stand back. I'm going first," followed by "You would still be hunting for this place without my guidance. I will be cured first," the player character will gain  +3. Alternatively, allowing her to be purified will gain the player character  +10. If instead selecting "Make way, Lae'zel. I am purging myself of this damned parasite" and subsequently committing to that decision, she will turn hostile against the party along with the Ghustil.

It is necessary to pass three saving throws in order to successfully complete the procedure.

• DC 12  Intelligence saving throw
• DC 15  Wisdom saving throw
• DC 18  Constitution saving throw or DC 18  Intelligence saving throw
  • Paladins, Bards, Fiend or Great Old One Warlocks and Sorcerers may make a DC 18  Charisma saving throw instead
  • Barbarians may make the DC 18  Constitution saving throw with advantage
  • Clerics and Monks may make a DC 18  Wisdom saving throw with advantage

Several classes have an additional choice for the third save, letting them use their main ability stat to more easily overcome the DC 18.

After the third step of the procedure, Clerics can select "Pray for deliverance, Flood the creature with divine power" for  +1. Finishing the procedure gains the party  +8.

If Lae'zel is the one in the machine, the saving throws happen automatically without player input. Lae'zel will often fail some of them due to usually having relatively low Intelligence and Wisdom scores, and there being no way to add bonuses. Regardless, the player character will gain  +1.

Secrets of the Zaith'isk

The Zaith'isk in use.

If picking the option "Examine the device" and passing a DC 15 Investigation check:

“

The device is an ingenious synthesis of illithid anatomy and metal alloys. It hums with psionic energy, hinting at paths into unknown minds and unseen planes.

„

If Lae'zel is convinced to leave the machine at any stage, be it by trickery or persuasion, the player character will gain  +1  +1  +1  +1  +1.

Stage one

You can persuade Lae'zel to jump out of the machine as soon as the procedure starts with a DC 30 Persuasion check. Alternatively, you can let the procedure continue and attempt a DC 30 Deception check to trick her out of the machine. A passive Perception check will tell you:

“

The zaith'isk's psionic forces batter Lae'zel's thoughts. There is no chance she will survive this unscathed.

„

Telling Lae'zel to endure ("Endure, Lae'zel. The cure is worth the torment.") gives  +1.

If the player character is in the machine and passes a passive Perception check:

“

You realize the device is hunting your parasite. But it's doing so blindly. Without direction, your faculties could be permanently damaged.

„

Stage two

If Lae'zel being in the machine and picking the option "Seek answers within the zaith'isk" and passing a DC 21 Wisdom check:

“

Lae'zel's life is laid bare among those that came before. Her thoughts are turned to silver thread and relayed to the Astral Sea. The voices of the dead cry out as one. The zaith'isk collects memories from the infected - and executes them. It is not for curing. It's for killing.

„

This decreases the difficulty of the Persuasion option to have Lae'zel leave the machine from 30 to 21. Succeeding will free Lae'zel and give  +1.

Alternatively, telling her to endure (Keep focused, Lae'zel. The cure is close.) gives  +1.

Stage three

If Lae'zel is in the machine, it's possible to persuade her to leave again. This difficulty will either be 21 or 30, depending on the previous choices. Attempting to deceive her remains a DC 30 Deception check.

Alternatively, a DC 30 Wisdom check or a DC 30 Arcana check will allow to force Lae'zel out of the device. The latter will also grant the Awakened buff.

If the player character is in the machine and succeeds on any option, it will give  +3.

Outcome

The failed saving throws will, respectively, give -2 to  Intelligence,  Wisdom, and  Constitution. Consuming a Mind Flayer Parasite Specimen with the affected character, either through the inventory or by unlocking an Illithid Power, will get rid of these debuffs. One specimen will get rid of all three debuffs; multiple are not needed.

If succeeding the DC 30 Arcana check in stage three, or succeeding all three saving throws, the parasite will strengthen and give the Awakened buff, which allows using all Illithid powers as a bonus action instead of a regular action.

Regardless of whether succeeding or failing, the zaith'isk will be destroyed by the Dream Visitor, who may exclaim, "Enough!".

If passing a DC 15 Deception check (or a DC 15 Performance check if the player character was in the machine) Ghustil Stornugoss will let the party leave. Otherwise, she will fetch assistants, locking the door ( DC 10 Sleight of Hand check) behind her. After some time passes, some Githyanki will barge in and try to kill the party. This will not cause the other characters in the creche to turn hostile, and it's possible to safely teleport to the nearby Sigil to avoid the fight.

External links

• Zaith'isk on the Forgotten Realms Wiki