PROFANE SPELLBOOK

You can take the Magic (Attune) action and expend X mana points to attune and transform a spellbook into a Profane Spellbook. Moreover, any spell granted by this Wizard Subclass option always appear in a newly transformed Profane Spellbook. The Profane Spellbook becomes a spellbook if you use this feature again or you die.

TWISTED FOCUS

You can take the Magic (Attune) action and expend X mana points to attune and transform an arcane focus you have equipped into a Twisted Focus. The Twisted Focus becomes an arcane focus if you use this feature again or you die.

FIENDISH SERVANT

The find familiar and summon fiend spells are added to your Profane Spellbook if you haven't already added them, you always have them prepared, and they don't count against the maximum number of wizard spells you can prepare.

When you use the Channel Corruption feature of your Profane Spellbook to cast the find familiar spell, the familiar's type is fiend and you can choose a small or smaller fiend of level 1 or lower instead one of the spell's options.

DEMONIC WARD

The magic circle spell is added to your Profane Spellbook if you haven't already added it, and you always have it prepared, but it doesn't count against the maximum number of wizard spells you can prepare.

When you use the Channel Corruption feature of your Profane Spellbook to cast the the magic circle spell, you can only target fiends in the spell's reverse direction, and the fiend summoned in the area of the spell is tamed by you for the duration of the spell, regardless of the spell's description. You can take the Command action to cause the fiend to move in and out of the magic circle freely thereafter. If the spell ends while the fiend still has hit points and the magic circle is still active, the fiend teleports back into the magic circle and acts according to the spell's description as normal. Otherwise, the summoned condition ends.

DIABOLIC STRINGS

The banishment and planar binding spells are added to your Profane Spellbook if you haven't already added them, and you always have them prepared, but they don't count against the maximum number of wizard spells you can prepare.

When you use the Channel Corruption feature of your Profane Spellbook to cast the planar binding spell, you can speak the fiend's true name and bind the fiend to a page of your Profane Spellbook, provided you target a fiend that has a level equal to half your wizard level or lower.

DARK EMPOWERMENT

You can add the planar ally spell is added to your Profane Spellbook if you haven't already added it, and you always have it prepared, but it doesn't count against the maximum number of wizard spells you can prepare.

When you use the Channel Corruption feature of your Profane Spellbook to cast the planar ally spell targeting a demon prince or equivalent, you can cause the summoned creature to make a Charisma saving throw. On a failed save, it becomes tamed by you until it completes the task you orders it to complete, and without requiring any payment, provided the task doesn't harm the fiend. The fiend has disadvantage on the saving throw if you say its true name as part of the summoning.

NINTH LAYER

You are immune to the charmed and frightened conditions caused by effects that originate from a fiend, and fiends are lethargic against you.