School of the Aether-Weave

Your study is the base form of magic and you can use your specialty to your advantage by modifying spells, whether they be yours or your enemies'. The weave of magic that makes up the world is what fascinates you.

Weaver's Eye

Beginning at second level when you take this subclass, you learn Detect Magic and add it to your spell book. This does not count against your total amount of learned spells.

You may can also cast Detect Magic without expending a spell slot. This feature can be used up to your intelligence modifier per long rest (minimum of once).

Weaver's Adjustment

Starting at 2nd level, when a creature that you can see within 30 feet of you casts a damaging spell at a level that you can also cast, you can change the damage type (but not the amount of damage die that are rolled) of that spell to one of your choosing. This ability can be used up to your proficiency score per long rest.

This feature only affects spells that are cast with an attack roll, spells that cause a "Saving Throw" are unaffected.

Unraveling of Threads

You can cast Counterspell at the third level without expending a spell slot up to your proficiency modifier per long rest. When using this feature you must cast it at third level (meaning the equivalent to a third level spell slot) and cannot use a higher tier spell slot.

If you do not have Counterspell in your spellbook then it is automatically added and does not count against your total amount of learned spells.

If you do not have Dispel Magic in your spellbook then it is automatically added and does not count against your total amount of learned spells.

Proficient Denial

Beginning at 10th level, when you cast counterspell or dispel magic, you add your proficiency bonus to that ability check.

Weaver's Aura

You have resistance against the damage of spells. 

Furthermore, any damaging magic that you deem hostile towards any creature of your choosing within 30 feet of you can also be reduced to half damage (this takes effect after the damage is rolled and does not affect the amount of die rolled). This feature can only be used as a reaction, up to half of your proficiency modifier (rounded down) per long rest.