Gunbreaker

The Hrothgar of northern Ilsabard have passed the art of the gunblade from one generation to the next. The weapon itself combines a sword with a firing mechanism, emitting a range of magical effects by utilizing authorially imbued cartridges. Originally employed by Queen Gunnhildr's personal guard, they were once known as "Gunnhildr's Blades" and differ greatly from the similarly named weapons used in the Garlean Empire.

Gunblade Proficiency

When you choose this archetype at 3rd level, you gain proficiency with Gunblades.

Gunblade Expert

When you select this archetype at 3rd level, you gain proficiency with Tinker's Tools; allowing you to create a personalized Gunblade over the course of a long rest using any martial melee weapon that you possess, your tinker's tools, and 50 gp worth of supplies.

Adept Martialist

When you choose this archetype at 3rd level, you learn to execute powerful cartridge abilities using your Gunblade.

Cartridge Abilities. You learn two cartridge abilities of your choice, which are detailed under "Cartridge Abilities" below.

You learn an additional cartridge ability of your choice at 7th, 10th, and 15th level. Each time you learn a new cartridge ability, you can also replace one cartridge ability you know with a different one.

Munition. You gain a number of munition points equal to three times your Constitution modifier (minimum of 1). You regain 1 expended munition point each time you roll a 20 on the d20 roll for an attack with a gunblade, or deal a killing blow with a gunblade to a creature of significant threat (DM's discretion). You regain all expended munition points after a short or long rest. You may use these munition points to load up to 6 arcane munitions into your Gunblade as a single Attack out of your Attack action.

Saving Throws. Some of your Cartridge abilities require your target to make a saving throw to resist the effects. The saving throw DC is calculated as follows:

Cartridge Ability Save DC = 8 + your proficiency bonus + your Strength modifier.

Royal Guard

At 7th level, your practice guarding those around you gives you experience not just on the battlefield, but during social encounters. You gain proficiency in both Insight and Investigation.

You also gain the following two new cartridge abilities:

Heart of Stone

When you or an ally within 30 feet are hit by an attack, you may use your reaction to expend two munition points, granting yourself or that ally a +3 AC bonus until the end of your next turn, including against the triggering attack.

Heart of Light

As an action, you can spend up to three munition points to grant an ally temporary hit points equal to your Constitution modifier + 1d10 per munition point spent.

Between Offense and Defense

Upon reaching 10th level, your Gunblade techniques improve, and your speed and ferocity in combat is unmatched. You add your proficiency bonus to your initiative. Additionally, you learn the Blasting Zone cartridge ability.

Blasting Zone

Whenever you use the Burst Strike feature of your Gunblade, you may spend an additional munition point. The damage of your Burst Strike increases by an additional 1d12.

Unbreakable Guard

Starting at 15th level, you have attained true mastery over the Gunblade. You gain the following traits:

Bloodfest. When you roll initiative and have no munition points remaining, you gain up to four munition points.

Fated Circle. Whenever you use your Demon Slice ability, you may spend an additional munition point to increase the damage by 1d6. In addition, any enemy that is Large or smaller that fails its saving throw is knocked prone in addition to being pushed back.

Superbolide

Starting at 18th level, when you or an ally within 30 feet are hit by an attack, you may use your reaction to expend the last of your remaining Cartridges. You become immune to damage until the end of your next turn. As long as the immunity lasts, if any creature within 30 feet would take damage, you may reduce that damage by 1d8 per cartridge expended by Superbolide. A creature may only benefit from this effect once. You can't use this feature again until you finish a long rest.

Continuation

Upon reaching 18th level, as a bonus action, you can expend a munition point to make an additional melee attack.

Cartridge Abilities

These cartridge abilities are presented in alphabetical order.

Aurora

When you use your Second Wind feature, you may expend two munition points to enhance its benefits. Upon using it, and at the start of your turn over the next 3 rounds, you gain hit points equal to 1d10 + your fighter level. Additionally, instead of healing yourself, you can extend this enhancement to an ally you can see within 30 feet of you.

Demon Slice

You can utilize two munition points to create explosive force in a circle around you as an action. Each creature within 5 feet from you must make a Constitution saving throw. On a failed save, a creature takes 4d6 thunder damage and is pushed 10 feet away from you. On a successful save, the creature takes half as much damage and isn't pushed. 

Improved Burst Strike

You are properly trained in the art of Gunblade combat. When using the Burst Strike feature of a Gunblade, your attack deals 1d12 thunder damage instead of 1d6.

Lightning Shot

You can use an attack action to utilize one munition point and make a ranged attack using your Gunblade. This ranged attack uses your Strength modifier and proficiency bonus to hit, has a range of 30 feet, and deals lightning damage equal to 1d10 plus your Strength modifier. On a successful hit, the target must make a Wisdom saving throw. On a failed save, the target has disadvantage on all attack rolls against targets other than you until the end of your next turn.

Rough Divide

You can utilize your gunblade to launch yourself forward. As a bonus action, you may expend one munition point to blast yourself towards an enemy. When you do, you move up to 15 feet toward a hostile creature you can see or hear. If you are within 5 feet of them after this movement, you can choose to impose a Strength saving throw against them if they are Large or smaller. On a failed save, you knock the target prone with a mighty tackle.