Alterant

Choose two Wizard spells from the Transmutation school, each of which must be no higher than level 2, and add them to your spellbook for free. In addition, whenever you gain access to a new level of spell slots in this class, you can add one Wizard spell from the Transmutation school to your spellbook for free. The chosen spell must be of a level for which you have spell slots. Lastly, as a Magic Action you can transmute your spellbook into any simple object weighing 1 to 3 pounds. The spellbook remains transmuted until someone touches it and takes a Magic Action to change it back, or until the object takes any damage.

When you cast a Wizard spell with a spell slot targeting only yourself and your allies, before the spell ends you can change it into a different Transmutation spell you have prepared without expending another spell slot. The rules for doing so are as follows:

Normal Casting. You cast the new spell as normal.

Timing. The old spell ends the instant the new spell is cast. The new spell lasts its normal duration, or the remainder of the old spell's duration, whichever is less.

Target Limit. The targets of the new spell must be chosen from among the targets of the old spell.

Effect Limit. The new spell is not considered to be cast with a spell slot. It is cast at the same level the old spell was, treating a level 6+ spell slot as if it were level 5, and it cannot grant Temporary Hit Points.

You have transmuted your own brain to protect the parts most important for spellcasting. When you fail a Constitution saving throw to maintain Concentration, you can choose to succeed the saving throw and take Psychic damage instead (no action required). The amount of Psychic damage you take equals the DC for the saving throw minus your saving throw result. This damage cannot be reduced in any way and does not provoke a Concentration saving throw of its own.

You always have the Polymorph spell prepared, and you can cast it as a Bonus Action. You can cast Polymorph once without expending a spell slot, and you regain your ability to cast it in this way when you finish a Long Rest.

By reusing wasted energy from your spells you can sculpt matter to bind and hinder your foes. When one or more creatures you can see succeed a saving throw to be unaffected by one of your spells, you can take a Reaction to force those creatures to make Dexterity saving throws against your spell save DC. Each creature that fails gains one of the following conditions as transmuted matter binds it: Blinded, Deafened, or Restrained (you choose for each creature). This feature's effect on a creature ends when the transmuted matter changes back at the start of your next turn, or when an affected creature ends it early by taking an Action on its turn to free itself. Once you use this feature, you cannot use it again until you finish a Long Rest, or until you expend a level 4+ spell slot to regain your use of it.