Welcome to Frustration's firepower Index, where I compare and rank the combat capabilities of Cosmere worlds and Magic systems. This thread will be focused on Feruchemy.
Feruchemist
Preparation: Be a koloss blooded, feruchemist. The body has room for 8 large bracers, which I recommend 2 goldminds, 2 steelminds, a pewtermind, a zincmind, and 2 nicrosilminds. They can also hold several smaller metalminds which can be surgically placed inside the body, including chromium, iron, brass, electrum, cadmium, and if possible extra gold, steel, pewter and nicrosil. Also in their possession should be, rings and earrings for the other metals. And an aluminum gun and bullets, as well as a set of grenades.
Note that the Nicrosil is used for making a perpendicularity, if the amount of investiture needed exceeds the amount that can be stored in two large metalminds with an implant switch those for other usable metals like gold, steel, pewter, zinc, and chromium.
Offenses: Increased strength and speed make them increadibly dangerous, especially with a gun, with zinc allowing them to almost instantly calculate trajectories. Additionally if they every get above an opponent they can tap iron to crush them, and grenades can blow up enemies.
Defenses: Gold allows the feruchemist to heal, and tin allows them to not feel pain, and with brass the feruchemist can become too hot to safely touch.
Mobility: Steel makes the feruchemist incredibly fast, storing iron allows them to safely fall from great heights, and tapping large amounts of Nicrosil allows them to cross between realms.
Stealth: Storing Nicrosil hides them from investiture detection, and storing Connection makes them harder to notice, additionally storing iron would make them lighter, allowing them to make less noise while moving, and storing brass would hide them from heat detection if that ever comes into play.
Awareness: Tin allows the Feruchemist to increase their senses, and Bronze allows them to stay awake and alert.
Additional abilities: Electrum allows the feruchemist to become more determined, and to overcome resistance. Chromium, Zinc and Copper would allow them to learn and adapt to almost any situation, making it almost impossible to outplay a prepared Feruchemist.
As always what did you think? Did I miss anything? And what should I work on next?