Siegemaster

Siegemasters are, as their description claims, masters of siege warfare. Those who follow this path are able to direct the flow of battle with unending firepower and durability. 

Enduring will

Starting from 3rd level, your hit dice becomes 1d12 upon choosing this subclass

Devastator

Deal damage equal to damage + strength modifier + dexterity modifier against targers beyond 30 ft at 5th level with all weapons, and deal double damage to objects, structures and stone-like creatures using melee weapons. Also gains either a battle cannon and crushing fists

Level 5: Desolation Incarnate

Starting when you choose this subclass at 3rd level,  if your target is within 30 feet or closer, you add both your Strength and Dexterity ability modifiers to your damage and hit rolls with ranged weapons

Flow of Battle

Gain the ability to ignore cover or gain half cover for a number of times equal to your proficiency modifier, regaining all uses after a short rest at 9th level

Enhanced Vitality

At 9th level, you gain the ability to heal 3d6 hitpoints for a number of times determined by your constuition modifier, recharging all uses after a short rest.

Titanic Might

At 15th level, either your strength and dexterity increases by 6, to a maximum of 26.

In addition, whenever you take an attack, you can deal an extra 2d12 damage, increasing to 4d12 at level 20. Given that you took a bonus action to ready that attack the previous turn or before combat, and that you did not move the previous turn, you are also immune to being pushed/ all knockback attacks, fear and to be charmed at 15th level, as well as resistance to any non-magical damage