Dreadnought

Dreadnought
Dreadnoughts are fighters known for their great strength and constitution. Trying to harm them will only hurt the attacker. Few can say that they have defeated a dreadnought in any form of athletic activity. However, this doesn't mean that they are invincible, just that they are hard to kill.

Earth Breaker
At 3rd level, you can use an Action to slam the ground with your fist, leg, or your weapon to shake the earth. Any creature of size class large or smaller within a 10 ft. radius of you must make a Dexterity saving throw DC equal to (8 + your Strength modifier + your proficiency bonus). On a fail, a creature is knocked prone. (Large creatures have advantage on the saving throw.)

The radius increases to 20 ft. at level 15 additionally large creatures no longer have advantage.

Armor Training
At 7th level, while you are wearing medium or heavy armor, any disadvantage caused by the armor you are wearing is negated, and when you become encumbered, you don't lose any movement speed.

Dreadnought Resilience
At 10th level, when an enemy critically hits you, you can treat the critical hit as a normal attack. You can do this a number of times equal to your Constitution modifier per long rest.

Strong as Stone
At 15th level, when you are forced to make a saving throw against being grappled, incapacitated, paralyzed, knocked prone, restrained, or stunned, you can spend your reaction to have advantage on the saving throw. Additionally, you can also make a melee attack against the person who forced you to make the saving throw, as part of the same reaction if they are within 5ft of you. you can do this once per short or long rest.

Unrelenting Will
At 18th level, when you are reduced to 0 hit points but not killed outright, you can choose to gain hit points equal to ( 2D10 + your fighter level ). You can’t use this ability again until you finish a long rest.