Deepfire Emissaries carry the word of something burning and primal from deep beneath the earth. Their power rises from a place so hot that stone flows and the air itself burns, and their righteous wrath can burn just as hot. However, like volcanoes themselves, these warriors create aswell as destroy, and the most powerful of them can raise islands out of the deep with some volcanic help. Most hail from island-based societies, but a few hail from volcanic mountain ranges in other parts of the world, and there is even precedent for having followed this path without previously having seen a volcano firsthand.
All Deepfire Emissaries hold similar tenets, regardless of any master they serve.
Authenticity. It is no virtue to see injustice and not be angered, to lose a friend and not be saddened, to see a sunset and not be moved. Feel your feelings and act upon them responsibly.
Decisiveness. Once the proper course of action is clear, every moment of delay is a cowardly waste.
Creativity. Every warrior should be able to build or create as well as destroy.
Ferocity. Your foes should fear your wrath and your friends should be grateful for your protection.
Add the earth and fire schools of magic to your list of herald spells.
At 3rd level when you choose this archetype, you gain the following two Channel Divinity options:
In response to witnessing an injustice or atrocity (or its after effects) you may use your reaction to erupt with righteous wrath. For the next hour, you have advantageous attack rolls and Intimidate checks against creatures involved in the triggering event, and your weapon attacks do an additional 1d6 fire damage to them. If you (with help from your companions) manage to slay all of the offending parties before the hour ends, you regain the spent use of channel divinity.
As an action, you may create one of the following. Unless otherwise noted, it must be created in an empty space adjacent to you. Items created this way are permanent, but subject to natural forces.
Also at level 3, you are blessed by the volcano to endure its scourges. You are resistant to fire damage, and you treat areas heavily obscured by smoke as lightly obscured and lightly obscured by smoke as clearly visible. Finally, you can walk across the surface of lava as if it were solid ground, not sinking or treating it as difficult terrain, though you still take fire damage as normal (albeit reduced by your resistance).
At 7th level, you have learned a potent ritual to enhance your weapons with the gifts of the volcano. You may perform this ritual, which takes an hour, on any piercing or slashing melee weapon. The weapon's cutting edges become razor-sharp volcanic glass and the weapon seethes with the heat of a volcano. While you (and only you) wield the weapon, successful attacks from the weapon do 1d4 ongoing damage for one minute unless an action is spent to stop the bleeding. The weapon also deals an additional 1d6 points of fire damage.
If the weapon is already made with volcanic stone (such as an obsidian-edged macuahuitl or an obsidian dagger or spear) the damage from both sources increases by one step, to 1d6 and 1d8, respectively.
Also at 7th level, you learn to create with what is available to you. You gain proficiency with two artisan’s tool sets of your choice, and when working with materials you gathered yourself (in other words, not purchased, but that you farmed, gathered, mined, fished, hunted, or harvested personally) no more than 20 miles from your current location, you gain an expertise die on your crating rolls. If the material is volcanic in nature (such as obsidian, pumice, or basalt), the expertise die increases by two steps, to a maximum of a d10.
At 15th level, you have fully absorbed the gifts of the volcano. You are immune to fire damage, smoke and ash no longer impede your vision in any way, you are immune to inhaled poisons, and you can breathe normally in areas of dense smoke.
At 20th level, you can create a new island where one did not previously exist. To do so, you must select an area of open sea at least 2 miles from any existing landmass. You must then spend a week’s worth of 8-hour days performing a magical ritual over the area, during which time a new volcanic vent opens and creates a new island with an area of 1d4+1 square miles. The surface is covered in rich volcanic soil that any plants native to the surrounding area will thrive in, and the process also magically stocks the surrounding waters with schools of fish suitable for fishing. Once you have used this ability, you cannot do so again for a year. Additionally, once you have used this ability 1d6 times, you must undertake some great task (Narrator’s discretion) to regain the ability to do so another 1d6 times.