Who am I? / I am the girl who loves my island / I'm the girl who loves the sea / It calls me
Since I anticipate a new UA article with sorcerous origins as soon as next Monday, now might be a great time for one that I've been pondering. Like a whole lot of people in America and abroad, I recently watched Moana, and I loved it. When it became clear that Maui was a 20th-level Circle of the Moon druid, I started thinking about how I might stat Moana, and along came the idea of the Tidal sorcerer, thanks to the surges of ocean water that frequently help her. (It's not my first sorcerous archetype based on a Disney Princess. Don't you dare judge me.)
Tidal Sorcery (Sorcerer)
A tidal sorcerer's contact with arcane power comes from the tides, and might be derived either from a connection to the sea itself, or to the moon(s) that control the tides. Many tidal sorcerers find that their moods reflect the tides as well: when the tides are high, they are generous, boisterous, or overbearing; when they are low, they are withdrawn, deceptive, or grasping. The sea holds an inescapable longing for them, especially for those forced by circumstance to live inland.
Born of the Shifting Tides
You gain a swim speed equal to your walking speed, and proficiency in water vehicles.
When you complete a short rest in or near a large body of water (including while aboard a ship), regain 1d4-1 sorcery points. Once you regain at least 1 sorcery point in this way, you cannot do so again until you complete a long rest.
Once you gain the Metamagic feature, you gain an additional metamagic option: Call the Tides. When you cast a spell of 1st level or higher, spend 2 sorcery points and choose one of the effects below. Once you choose an effect, you cannot use that Call the Tides option again until you have used all four Call the Tides options, or you complete a short or long rest.
High Tide: Creatures targeted by your spell must roll a Strength saving throw or be pushed 10 feet in a direction of your choice. Your allies can voluntarily fail this saving throw.
Flood Tide: Creatures targeted by your spell gain temporary hit points equal to your Charisma modifier + the level of the slot expended for 1 minute.
Ebb Tide: Creatures targeted by your spell take acid damage equal to your Charisma modifier or the level of the slot expended, whichever is greater, in addition to any damage the spell normally deals.
Low Tide: Creatures targeted by your spell cannot use reactions until the beginning of your next turn.
Above or Below the Waves
At 6th level, add water breathing and water walk to your Spells Known. These do not cost you a Spells Known slot. You gain the ability to cast them as rituals as well. Alternately, when you expend a spell slot to cast them, you can do so as a reaction. Water breathing and water walk spells that you cast cannot be dispelled by anyone other than you.
Tides of Fortune
Starting at 14th level, when your roll on an attack roll, saving throw, or ability check is a natural 2, 3, 4, or 5, you can add 10 to the result. Once you do so, you must complete a long rest before you use this feature again. You also regain the use of this feature each time you roll a natural 1 on an attack roll, saving throw, or ability check. The 1 must be the roll's final result; for example, if you rolled a natural 1 and a natural 15 while you had advantage, you would not regain use of this feature.
Additionally, when you roll a d100, you may roll twice, learn the effects of both rolls, and choose whichever you prefer. Once you do so, you must complete a long rest before you use this feature again.
Soul of the Sea
Starting at 18th level, when a spell you cast would deal cold, fire, lightning, or thunder damage, you can convert the spell's energy to a gout of seawater, dealing bludgeoning damage as if with a magic weapon. At the DM's discretion, creatures that are vulnerable to cold damage may also be vulnerable to damage from seawater.
Further, add control water to your Spells Known. This does not cost you a Spells Known slot.
The awkward thing about the Tidal sorcerer is that I want Call the Tides to be available as soon as you have metamagic of any kind, because I think it's central to the archetype's playstyle - waiting until 6th is not great. So I'm stuck giving you a feature at 1st that you can't use until 3rd. Well, you get other stuff from that feature that you can use earlier, so... whatever, I guess. I'm also concerned that Call the Tides is burdensome on data tracking, since (at mid-to-high levels) it would really like you to complete the tidal cycle and start on a new cycle within a single encounter.
The other thing about Call the Tides is that I want it to nudge the player into varying up what they do with their actions - that's why the second feature is beneficial. I'm not sure I have these four options completely refined yet, though. If the Call the Tides structure does work well, I'd extend it to a Lunar sorcerer and a rework of the 4e Cosmic sorcerer, so if you're willing to provide feedback (or, God bless you, playtesting), this is the piece that interests me most.
The second element of Born of the Shifting Tides - sorcery point recovery - is small enough to nearly be a ribbon, but it's just useful enough to get Tidal sorcerers to want to sit and brood while gazing at the sea. It's there to push the image, basically.
Above or Below the Waves shores up (ha ha I made a pun) the sorcerer's already strong utility functions - you don't have to spend your precious Spells Known slots to cover theme here, because the subclass does it for you. Also, dispel magic when you're relying on water breathing to survive is a classic dick move from aquatic spellcasters, and I wanted to restore some equal footing for the Tidal sorcerer there.
Tides of Fortune is, as much as anything, about the narrative twists and turns of Moana's life. I'm also emphasizing the tides as a metaphor for any kind of changing circumstance, and I hope this captures it.
Soul of the Sea is a way around most kinds of damage resistance or immunity, but beyond that it's largely cosmetic. Anything that is vulnerable to cold because it is wholly or largely composed of fire should probably be vulnerable to seawater damage as well.