Forgeheart

You are a prodigy of creation and metallurgy. A sage of steel. Whether because of an ancient tradition passed down that you inherited, a connection to the powers of earth or fire, or simply a divinely given talent, you can unlock potential in weapons that seem mundane to most, and can create what few others can.

Whether it is because of your burning will, subtle touch, or your silvery tongue, when you command, the armaments of war obey, reshaping as easily as within the fires of a mighty forge.

CONCEPT: a subclass that interacts with weapon properties, enabling things like dual-wielding two-handed weapons and bows. The hidden arsenal ability allows the fighter to leverage their versatile weapon and armor proficiencies, quickly remove heavy armor when stealth is needed, and replace it if stealth fails. Also helps the fighter replace thrown weaponry on the fly. A mixture of "Legendary Swordsmith" tropes and a metal-themed magic.

Maker's Touch

At level 3, you can choose to gain one of the following benefits:

Powerful Build. You count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift.

The ability to cast Mending.

Proficiency and Expertise in Smith's Tools.

You also gain the ability to add a property to a weapon you hold, as a bonus action. You may have up to two properties active at one time. (You may have three active properties at level 10, and four at level 18.) If you are no longer holding an affected weapon at the end of the turn, it returns to normal.

The properties you may add are: Finesse, Thrown, One-handed, Light, Reach. 

(Light and one-handed replace heavy and two handed, respectively.)

 

Hidden Arsenal

At level 7, you gain the ability to reduce metal weapons and armor to simple charms, jewelry, or pendants, with symbols on each to represent what they are. you may, at will, return the items to their original forms and equip them. You cannot manifest more items than you can wear (Armor) or hold (Weapons) at one time. Creating a charm takes ten minutes with smithing or jewelers tools that you are proficient with, or an hour without. Manifesting, equipping, and reducing these items once they have become a charm is instantaneous, and can be done as a free action.

 

Maker's influence

10th You may now add a property to a weapon you are holding as a reaction, and for one round you may add a property to another weapon you can see within 30 feet. You may now also add the properties Heavy or Two-handed to weapons.

 

Legendary Craftsman

15th level

You may spend eight hours performing a legendary feat of creation. You may do one of the following

-enhance up to 100 weapons of your choice that, for the purposes of overcoming resistances are considered silvered and magical for as long as they remain with the first person to wield them since the enhancement.

-create or enhance a weapon of your choice that deals an additional 1d4 of a damage type of your choice.

- another roughly equivalent feat approved by your DM.

after the first feat of legendary creation, any subsequent uses require an extremely amount of treasure for materials.

Pulse of the Forge

18th level: Whenever you use an action surge or second wind, if you have all four weapon properties active, you gain advantage on your next attack.