Construct

You have practiced and mastered the art of Artifice on yourself - creating a better body so that you may live forever. Your unique combination of technical ability and spellcraft has allowed you to weave your consciousness among a body that is uniquely difficult to kill and has become a weapon of destruction.

Construct Spell list

As you enhance your physical form with mechanical parts, you gain additional spells. Starting at 3rd level, you always have certain spells prepared after you reach particular levels in this subclass. These spells count as artificer spells for you, but they don't count against the number of artificer spells you prepare. 

• 3rd level: False Life, Heroism
• 5th level: Aid, Mirror Image
• 9th level: Magic Circle, Vampiric Touch
• 13th level: Death Ward
• 17th level: Antilife Shell, Reincarnate

Subdermal Steel

When you select this subclass at 3rd level, your body has become more mechanical than organic. When not wearing armor, your AC equals 10+DEX+INT. You can still benefit from a shield. You also gain proficiency with heavy armor, as well as proficiency with Smith’s tools which you can use as a focus for your artificer spells.

Additionally, you have altered your body so that your hands are natural weapons. You can use your intelligence modifier instead of strength or dexterity for attack and damage rolls with your unarmed strikes, which deal 1d8 bludgeoning damage. This increases 1d10 at 9th level.

Mechanical Regeneration

Also at 3rd level, you are able to heal your wounds with tinkering alone. You learn the Mending cantrip. If you have Smith’s tools or Tinkerer’s tools and are using them as a spellcasting focus for your artificer spells, you can cast the Mending cantrip on yourself and heal an amount equal to 1d6+your spellcasting ability modifier. This increases to 2d6 at 15th level. You can do this a number of times equal to your proficiency bonus per long rest. 

Extra Attack

At 5th level, you have begun to craft your body for war. You can attack twice instead of once whenever you take the attack action on your turn. 

Body of Artifice

Additionally at 5th level, your synthetic nature allows you to incorporate your artificer infusions into your body. If you have the artificer infusions Arcane Propulsion Armor, Armor of Magical Strength, Enhanced Defense, Enhanced Weapon, Radiant Weapon, or Resistant Armor, you can infuse them into your body, rather than into a suit of armor or weapon. You may infuse yourself with one armor infusion and one weapon infusion at a time. If you attempt to infuse yourself with a second armor or weapon infusion when you already have one, the first one will dissipate. If you are wearing armor, you can only benefit from the infusion held by the armor. You can still infuse a shield and benefit from your armor and shield infusions. Your unarmed strikes count as magical for overcoming resistances and immunities when they are enhanced by one of your infusions.

Synthetic Soul

At 9th level, when you hit with an unarmed strike on your turn, you can use your Mechanical Regeneration healing ability on yourself as a bonus action, and you do not need your tools to cast it.

Additionally, you have infused your soul into your mechanical body parts so that you may fight off death. When you are brought to 0 hit points but not killed outright, you can use your reaction to expend an artificer spell slot to instead remain conscious. The amount of HP you obtain when you use this feature equals the spell slot level plus your intelligence modifier. You can use this feature as long as you have spell slots available.

Constructed Creature

At 15th level, you are more construct than organic, having infused your entire self with metal in some capacity. As such, you gain the following benefits:

• In addition to their normal damage, your unarmed strikes now deal an additional 1d8 force damage.  
• Your armor class increases by +1
• The amount you heal through Mechanical Regeneration increases to 2d6.

Additionally, you have mastered your ability to infuse your own body. Any infusion that you would normally put in an item of clothing you can instead infuse into yourself. This includes Boots of the Winding Path, Helm of Awareness, and Mind Sharpener. If you use one of these infusions in this way, you can still wear armor, clothing, and accessories that have magical properties or additional infusions and benefit from both. For example, you could wear a Headband of Intellect and have the Helm of Awareness infusion within your body and benefit from both.