Specializing in armor and the crafting of your  well fitted suit, you stride into battle to help your allies and soak up the damage.

Well Fitted Suit

When you select this archetype at 3rd level, you begin to learn the intricacies of armor craftsmanship. You can convert a medium or heavy suit of armor into a well fitted suit (WFS) of armor. This particular suit of armor is crafted to your  exact specifications, and can only be proficiently worn by you. Your WFS gains a +1 bonus to AC (or increases it's bonus by +1, to a maximum of +3), and the armor's strength requirement is lowered by 1. Additionally, a WFS can be dodged and donned in 1/10 of the time. Should you lose your WFS or should you wish to fit another suit, you may do so with 24 hours of work and costs 100 gp worth of materials.

Metallurgy

At 3rd level, you gain proficiency with blacksmith tools. Additionally, you unlock some great technique of forging that you can use to upgrade your armor. At 3rd level, you learn three Crafting Techniques, and two additional techniques  at levels 7,10, 15, and 18. You keep your knowledge of techniques  is a special crafting manual. You may learn additional techniques  from adventuring or meeting other craftsmen, doing some requires you to spend time and gold as if you were copying spells into a spell book (assume basic techniques  are level 1 spells, apprentice  techniques  are level 2, etc.)

Crafting techniques are separated  into 5 basic levels: Basic, Apprentice, Journeyman, Master, and Legendary. Unless otherwise noted a given suit may only have one of each type of technique applied to it. Applying a crafting technique to a suit requires time, tools, and the appropriate materials:

Basic: 100 gp and 1 day of work

Apprentice: 200 gp and 3 days of work

Jouneyman: 300 gp and 5 days of work

Master: 400 gp and 1 week of work

Legendary: 500 gp and 2 weeks of work

When you learn a new crafting technique, you may apply it to a WFS immediately  at no cost, though you must still pay for any additional materials required in the technique description, if any. 

Saving throws: If an effect of wearing your WFS calls for a saving throw, it is calculated  as follows:

Armiger save DC=8+proficiency  bonus+Int modifier

Adamantine Plating

Your WFS gains the properties of adamantine armor. You may not apply adamantine and mithril plating to the same suit. Your suit must be medium or heavy to accept.

Aquatic Plating

You learn how to blend water elemental essence into your armor allowing it to move effortlessly in the water. While wearing your WFS, you gain swim speed equal  to your movement speed, gain resistance to cold damge, and can breathe underwater.

Bladed Armor

You install a set of retractable  blades unto the bracers of your WFS. Your blades are light, finesse weapons and deal 1d8 slashing or piercing damage. You cannot be disarmed of these blades and you gain advantage on Sleight of Hand checks made to conceal them. You may replace the blades with the blade of a magical sword, or have one or both blades enchanted. You may hold or otherwise maniplate a weapon, shield, or other object on the same arm as your arm blades, though you may not attack and use an object or weapon held in that hand on the same turn.

Boot Springs

You install a pair of high tension sings in the boots of your armor. While wearing your WFS, you may use a bonus action to triple your jump distance for that turn, and your jump distance is not limited  to your movement speed. Your suit must be light or medium armor to accept. 

Cushioning Underlay

You learn to pad your armor with owl bear down in just the right place to prevent falling damage. While wearing your WFS, you are immune to falling damage and gain resistance  to bludgeoning damage. 

Darksteel Plating

You learn how to blend darkstone, stone infused with necrotic energy, into your steel. You gain resistance to necrotic and radiant damage while wearing your WFS. Your suit must be heavy to accept.

Deep Crystal Studding

You learn how to stud your underlying leather with deep crystal, crystal infused with latent psychic energy. You gain resistance  to force or psychic damage while wearing your WFS. Your suit must be light or medium to accept.

Dragonscale Underlay

You learn how to best utilize dragonscale in the production of heavier armors. Select two damage types (acid, fire, lightning, poison, thunder): while wearing your WFS, you gain resistances to those damage types.

Durable Plating

The magical AC bonus of you WFS increases by +1, to a maximum of +3.

Hooked

You add a series of discreet and retractable hooks to the gauntlets and boots of your armor. While wearing your WFS, you gain climb speed equal to your movement speed. Your armor must be light or medium to accept.

Immortal Plating

You learn how to blend celestial essence into your steel; this essence  knits your wounds back together at a very alarming rate. While wearing your WFS, while you are below half your HP maximum and have at least 1 HP, you heal 4 HP at the beginning of each of your turns. This stacks with Living Wood Underlay.

Impenetrable Plating

The magical AC bonus of your armor increases by +1, up to a maximum of +3.

Installed Crossbow

You attach a hand crossbow and loading mechanism to your WFS. You have advantage on Sleight  of  Hand  checks made to conceal this crossbow. Should you wish to, you may replace this crossbow with any magical light or hand crossbow, or you may have this crosshow enchanted. The crossbow deals 1d6 piercing damage, and ignores the loading property  allowing you to make as many attacks with it as you have each turn.

Invincible Plating

You learn how to blend earth elemental essence  into your steel, making your armor nigh indestructible  to certain forms of strikes. Select with slashing, piercing, or bludgeoning  damage: while wearing your WFS, you are immune to that type of damage. Your suit must be heavy to accept.

Juggernaut Plating

You install a set of reinforced shoulder plates and a reinforced  helmetc on your armor, turning you into a veritable battering ram. While wearing your WFS, you may, as an action, move up to your speed towards an inanimate object (this includes buildings, walls, gates, etc.). At the end of this movement, you hit the object, dealing 3d6 + twice your level bludgeoning  damage which ignored the objects damage threshold. Your suit must be have to accept.

Living Wood Underlay

You apply a thin layer of living wood to the underside of your armor's plating. This wood seeps a restorative sap into your skin. As long as you are wearing your WFS, while you are below half of your HP maximum  and have at least 1 HP, you gain 1 HP at the start of each of you turns.

Magnetic Plating

You learn to blend lode stone into your armor plating, all the better to draw attacks to your impenetrable shell. While wearing your WFS, any ranged weapon attacks made with metal ammo or melee attacks that target an ally within 10 ft of you instead target you. A creature welding a metallic weapon may make a strength save to target someone else. You and your allies are not affected  by this. Your suit  must be heavy armor to accept.

Mithril Plating

Your WFS  gains the abilities of mithril armor. You may not apply mithril and adamantine  plating to the same suit. Your suit must be medium or heavy armor to accept.

Modular

You alter your WFS to be adjustable on the fly. As an action ypu may readjust, remove, or attach parts of your armor; doing so allows you to shift your suit between light (studded armor), medium (half-plate), or heavy (full plate) armor forms. You may apply additional techniques  to a modular suit. One of the forms maintains this technique and the other forms are upgraded as if they are separate suits. Applying this technique to any other armor besides full plate requires additional materials: 1500 gp if the suit is light, 1000 gp if the suit is medium, 500 gp if the suit is heavy.

Molten Plating

You learn how to blend fire elemental essence  into your steel, seeping heat into your attacks and granting you resistance to the same. While wearing your WFS, you gain fire resistance and your attached weapons deal an additional 1d6 fire damage per strike.

Reinforced

Your learn how to increase the toughness of your steel. While wearing your WFS, you reduce all non-magical slashing, piercing, or bludgeoning damage by 2 points. This reduction does not stack with other forms of damage reduction, including resistance. Your suit must be medium or heavy to accept.

Retractable Shield

You install a retractable shield into one of your bracers. As a bonus action, you may retract or deploy your shield. You may enchant this shield or replace this shield with any other magical shield in its place. Your suit must be medium or heavy to accept.

Second Skin

You learn how to craft your armor to be more breathable, light, and flexible, without compromising it's protective ability. Your WFS max Dex bonus increases by 1, it no longer applies disadvantage on skill checks, no longer applies disadvantage on skill checks, and no longer imposes any penalty for sleeping in it. Your suit must be medium  armor to accept.

Spiked

You add a layer of retractable spikes unto the knees, shoulders, gauntlets, helmet, and boots of your armor. While wearing your WFS, your unarmed strikes deal 1d4 bludgeoning in piercing damage. Your suit must be medium or heavy to accept.

Windswept Plating

You learn to blend air elemental essence  into your steel, allowing your armor to nearly float in the air and move swifter than the wind. While wearing your WFS, your base speed increases by 10 ft and you gain the ability to fly at your normal movement speed. You must start and end your flight on solid ground; otherwise you will fall immediately. Your suit must be light or medium  to accept.

Shining Armor

Starting at 7th level, when you roll initiative, the first hostile creature that sees you wearing your WFS (or nearest hostile creature, if multiple creatures can see you) must make a Wisdom saving throw. On a failure, the creature has disadvantage  attacking any target other than you for up to 1 min. At the end of its turns, an affected creature may repeat this saving throw, ending the effect with a success. The effect also needs if you are knocked out or the target loses sight of you. Any creature that succeeds this saving throw, can't be affected by this ability again for up to 24 hours.

Wall of Iron

Starting at 10th level, as a reaction, you can move up to half your movement speed and interposed yourself between a willing ally and a damaging attack or effect that you can see, either stepping in front of an ally or pushing that 5 feet.if you block an attack, the attack now targets you instead, and your ally is unaffected. If you block a damaging effect, you take on the whole effect, though you are allowed a saving throw. Your ally is unaffected, even if they are still in the area of effect.

Craftsman's Eye

Starting at 15th level, as an action, you can make a single melee attack against a creature you can see wearing manufactured armor. On a hit, the target must make a Dex saving throw or attacks made against it have advantage until it removes that set of armor. At the end of each if the creature's turns, the target may repeat this saving throw, ending the effect on a success. Additionally, you can spend 10 mins reinforcing an ally's suit of armor. While reinforced, this armor negates the first critical hit received by its wearer, turning it into a normal hit. After this attack, the armor is no longer reinforced.

Master Craftsman

At 18th level, you learn to craft adamantine armor, mithril armor, and dragonscale armor. Doing so requires 1 week of time and 500 gp (for mithril and adamantine) or 5000 gp (for dragonscale) in special tools and raw materials plus the cost of the suit of armor. Adamantine and mithril can be any form of medium and heavy armor, and dragonscale may be any form of light or medium armor.