Linebreaker

A Goliath with his shield in one hand and his greataxe in the other stands side to side with his brothers in battle, facing a formation of heavily armored silver Dragonborns. The hour is dire and they have been driven back far towards the bogs of the Evermoors. The Goliath knows they can't keep their formation in those lands and so he must break their line here and now. With a precise blow he smashes a Dragonborn to the ground. A single kog in the machine of war being torn away, this is the moment they have been waiting for. The Dragonborn can't close the formation in time and so the goliaths wash over them like a sea of metal, flesh and blood. The Talons of Justice have been routed, all thanks to a single soul with the power and determination of a battering ram.

A single Linebreaker cracking a formation in battle can lead armies to victories. As their skills are so valuable in war, Linebreakers are often mercenaries selling themselves to the highest bidder and sending the money to the king they belong to. The best Linebreakers are said to cost small battalions of normal soldiers. 

Restriction: Powerfull Build

Races with powerful build have the physique necessary to become linebreakers, only they are able to effectively wield the equipement needed to break enemy lines while using armor and shield to protect themselves.  

Improved Grip

Beginning when you choose this archetype at 3rd level, when you are wielding a shield with which you are proficient your Versatile weapon damage counts as though you are wielding it with two hands.

Shieldbreaker

At 7th level, you master the ability to break through tough enemies. As a reaction, when a creature within 5 feet of you ends it's turn without moving at least 5 feet, you can make one melee weapon attack against that creature. If you hit, that target must succeed on a Strength saving throw (DC equal to 8 + your strength modifier + your proficiency bonus) or be knocked prone.

You can use this feature a number of times equal to your Constitution modifier (minimum of once). You regain all expended uses when you finish a long rest.

Superior Grip

Starting at 10th level,  when you are wielding a shield with which you are proficient you may wield a Two-Handed melee weapon as if it doesn't have this weapon property.

Bastion of defense

At 15th level, you become a bastion of defense. you gain advantage on strength saving throws and gain advantage on strength checks to resist or escape being grappled.

In addition, with a reaction you can use a reaction to give an allied creature within 5 feet of you these same effects. 

Legendary constitution

At 18th level, your form becomes immutable and your capabilities to destroy structures do not limit themselves to creatures alone. Giving you the following effects:

• You become immune to any spell or effect that would alter your form.
• You gain advantage on Saving Throws against Spells and other magical Effects.
• You deals double damage to objects and structures