Rikishi

A sumo wrestler is a martial artist focussed on body weight.

Dohyou

When you choose this subclass at 3th level, you can declare your own fighting arena. As an action, you can define a circle with a 15 feet radius with its centre up to 15 feet from you as your wrestling arena. You also gain temporary hit points equal to your charisma modifier times the number of enemies inside the circle. You also gain a +1 bonus to your attack and damage rolls.

When you move your opponent outside the arena's range, knock him prone or shove him, you refill your temporary hit points gained from this action to an amount equal to the number of remaining enemies in the ring times your charisma modifier.

If you step out of the ring when there are still enemies inside the ring, get knocked prone or get shoved inside the ring, you lose face, which means you take psychic damage equal to your charisma modifier times the number of remaining enemies inside the ring and a -1 bonus to your attack and damage rolls as long as you are outside the ring.

Living Boulder

At 7th level, you gain advantage against getting displaced, knocked prone and rolls in order to shove an opponent.

Charger

You gain the Charger feat while inside your Dohyou.

Living Mountain

Starting at 15th level, whenever you succeed on a saving throw against getting displaced, knocked prone or successfully shove a creature, you gain temporary hit points equal to your charisma modifier.

Sekitori

When you are inside your wrestling ring, you gain temporary hit points equal to 6 + your charisma modifier at the start of each turn. The bonusses and penalties you get from fighting in or leaving your Dohyou are doubled.