An unarmed subclass.
If a Zephyr is quick and snappy, this guy is dense and tanky.
Level 3
Manhandle.
After you HIT with an unarmed strike, you may spend and roll 1 Hit Die to push the target a number of spaces equal to the result, or to grapple them (adding the result to the DC).
Metal Fists.
While unarmed, add 2x the STR requirement of your armor to your Defense and unarmed strike damage. Gain proficiency in Plate armor.
Level 7
Helmet Headbutt.
(1/Encounter) Add your Defense to the damage of an attack against a grappled target.
Level 11
Mighty Punch.
Your unarmed strikes gain: On Crit, the target becomes Prone.
Level 15
Metal Fists (2).
While unarmed, add the STR requirement of your armor to the result of your Hit Dice rolls.