Given the number of threads that have popped up recently around casters and how their design could be evolved in the future, I figured it'd be worth posting a brew I made a while back that's relevant to the subject matter. The starting point was: what would a thematic caster look like? A lot of players mention dedicated blasters, and I think this can be extended to any sort of specialty, like controlling, buffing/debuffing, and healing, and can all be expressed in roleplaying and flavor terms as well, like a light mage or a poison mage. The intent behind this homebrew class was to be able to express a variety of different themes in as simple a framework as possible.
For reference, here is the link to the class, which I'll summarize below.
The pitch behind the Paragon is: a thematic caster who revolves around a conceptual sphere of power, casting a very small number of spells based on a handful of traits more freely than other, more generalist casters. Because this kind of topic tends to be contentious, let me start by listing the tradeoffs this caster makes, just to make it clear I'm not trying to develop an overpowered class:
The Paragon gets the HP and defenses of a Wizard, so they're extremely squishy.
The Paragon gets the smallest spell list out of any caster, only being able to choose spells fitting their chosen narrow theme.
The Paragon also gets the smallest spell repertoire out of any caster, culminating at ten spells and two cantrips at 19th level.
With that established, let's talk about the cool things the class does:
Your spellcasting revolves around a sphere of power, effectively a collection of traits. Your spell list is formed of all the spells with your sphere of power's traits, transcending the normal limitations of spell traditions. If your sphere of power is sound, for example, your spell list will have spells with the auditory or sonic traits, and if your sphere is shadow, your spell list will instead have spells with the darkness or shadow traits.
You don't have spell slots. Instead, you start with 3 Focus Points, and can cast spells from your repertoire as if they were focus spells, allowing you to cast your spells without worrying about daily attrition. The only exception is 10th-rank spells, for which you eventually get a regular spell slot to cast.
You get a focus cantrip, destruction, that guarantees you can always deal damage even if you pick a sphere with few to no damaging spells. Many feats will also let you modify your cantrips and spells, with some also catering to your sphere by giving you new abilities related to one of your sphere of power's traits.
You start with a unique class feature, Rewrite Reality, that converts hard counters against you into soft counters: if an enemy's immune to your limited spells, you can still affect them, and convert their immunity into a high amount of resistance instead.
Effectively, you sacrifice pretty much everything, including the generalist versatility typical of casters, in exchange for being able to excel at your chosen specialty. You'd still be more versatile than most martials, but would be a lot less versatile than any caster, and wouldn't have quite the same uptime on your powerful effects as martial classes either.
