Ironclad Muscle v4

Weapons are made of metal. Your armor is made of metal. A mailed fist is as good as a mace as far as the one getting hit is concerned.

• While wearing heavy armor, all unarmed attacks have damage their damage die upgraded. (d4 to d6, d6 to d8 etc)
• While wearing magic heavy armor, the armor confers its magical AC bonus to your unarmed to hit and damage rolls. Your unarmed attacks are considered magical for the purpose of overcoming resistance and immunity. Armor counts as a weapon for the purpose of buffs from spells and the like. (Smite spells or any effect that requires a melee weapon attack) 
• While wearing heavy armor that consists of silver or adamant, your unarmed attacks will benefit from the Silvered or Adamantine weapon properties.  
• The Two-Weapon Fighting rule will apply to your unarmed attacks. After making a unarmed attack action, you may make a one handed unarmed strike as a bonus action, one your ability modifier will only affect the to hit roll.