Spell Siphon

[Zoken44]

Creation for the sake of creation. I welcome critique and input.

The idea being it is a 2 slot per rank class, but at early levels it does not recover spell slots on long rests. They do have an special reaction that allows them to consume magic and magical effects to refill spell slots. they can use the refocus activity to draw in ambient magic to restore spell slots, which would allow them to use spells at early levels, when magic items and other ways of restoring their magic is rare. They would obviously have cantrips.

They would have a spell sink (spelbook/familiar/spell-cache) where they can learn a new spell at each level, but if they critically succeed their reaction to consume a spell, it can be added to their spell sink regardless of the school.

The school you can automatically learn from is based on your subclass.

Neutrality: grants the divine school. you get a bonus to your reaction to consume magic verses spells and effects with the holy, unholy, vitality, and void traits. and if someone restores your hit points using magic you can restore spell slots equal to healing/ your level no more than your max spell slots.

Depression: Grants the Occult school, you get bonuses to consume spells with the mental and emotional trait, and if you critically fail a save against a spell with the mental or emotional trait, you regular fail instead.

Vacuum: grants the Primal school: you get bonuses to consume innate spells, and magical effects produced by creatures directly (such as a dragon's breath attack). your consume magic reaction also deals void damage to living creatures, and spirit damage to undead.

Null: grants the arcane school, admittedly this is where I lose ideas.

[Teridax]

I quite like the basic idea of a class with a low number of spell slots that can regain spell slots in the day, and the Wellspring Mage class archetype sets a precedent for this sort of mechanic. Being a really good anti-mage also sounds like an interesting niche to give a class so long as the reaction isn't too overwhelming, and that kind of reaction could be made to give many players what they currently feel is lacking in Counterspell.

Here are my criticisms and suggestions:

I'd be mindful of how this class is supposed to work at all levels when they don't encounter spellcasters. Being able to recover spell slots of any rank by Refocusing, not just low-rank slots, could be a possible fallback option.

Although I really like the idea of being able to cast a spell that you crit-succeeded against on your reaction, being able to derive a permanent benefit from it I think risks creating an exploit where your class could just have another party caster spam spells at them until they learn those spells, or do the same with items that let you cast spells. I'd probably make the benefit temporary, if still effective.

"Restore spell slots equal to healing/your level" may need a bit more detail, as I could easily see this also becoming an exploit (for instance, using heal on yourself to also refill your spell slots, or having two of this class just heal each other for neverending spell output), though that's not strictly necessary for a high-level overview like this.

If you're looking for ideas for the Null subclass, you could gain a bonus against magic generated from items, and any creature you use your reaction against could take a penalty to its Hardness, if it has any.

I'm quite curious to see more about this class's reaction in particular: does it work like Counterspell where you try to counteract a spell, or is it more of a reaction you use when you yourself would be affected by a spell?

[Zoken44]

the reaction Consume magic:
trigger: a spell being cast or magic effect activating and you are the/a target or included in the Area of Effect.
Make a spell attack roll against the spell save DC or DC of the effect.

Critical Failure: You are so preoccupied trying to consume the magic, it give you a penalty to your saving throw against the attack -1 circumstance

Failure: You regain spell slots equal to the spell rank -1, or the level of the magical effect, divided by 3 (in both cases a minimum of rank one slot) (For example if it was a 4th rank spell, you'd have 3 ranks of spells to recover, so a rank two and a rank one, or two rank ones, or one rank three)

Success: as failure, but you (and any other creature included in the spell or effect) also gain a +1 circumstance bonus to your save, and resistance to any damage from the spell or effect equal to your level until the end of your turn
Critical success: as success, but the origin must roll a DC 10 flat check on a fail, the spell fails, though the slot or other resource used to cast or produce it is still used. If this was a spell, you gain the ability to cast or produce this spell as an innate spell (using your Spell Siphon attack modifier and DC). you may choose to expend the use of the spell and make an appropriate skill check (the tradition of the caster) to add the spell to your sink. if you fail, you cannot attempt to learn this spell again for a day.