Tortle Linebacker (Path of the Shellshocker)

Shellshockers are fierce tortles who have developed a unique fighting style.  They rely on their massive shells to perform brutal charge attacks that send their foes flying.

Quick Withdrawal

At 3rd level, you can almost instantaneously withdraw your exposed body parts into your iron-hard shell.  As a reaction when you suffer a critical hit or are hit by a sneak attack, you can turn that attack into a normal hit.  Any effects triggered by a critical hit or sneak attack are canceled.

Shellshock

When you take this path at 3rd level, you learn how to wield your hulking shell as a weapon.  When you use your action to Dash and move at least 15 feet in a straight line, you can spend a bonus action to momentarily withdraw your head into your shell and make a full-on tackle.  You can use this bonus action to simultaneously enter a rage.  Make a melee weapon attack roll.  This attack counts as using a two-handed weapon.  If the attack hits, it deals 3d6 + your Strength modifier bludgeoning damage and if the target is no more than one size larger than you, it has to make a Strength saving throw against a DC of 8 + your proficiency bonus + your Strength modifier.  If it fails, it is knocked prone and pushed up to 15 feet away from you.

You cannot use this attack if you first move more than 10 feet away from your target before moving toward it.  For example, you cannot move 15 feet away from your target, then move 15 feet toward it and use this attack.  At 5th level, this attack does double damage.

Roll

Starting at 6th level, you learn how to use your unusual shape to literally roll with the punches.   As a reaction when you take damage, you can move up to half your movement speed away from the source of the damage.  This movement doesn't provoke opportunity attacks.

Once you use this feature, you can't use it again until you finish a short or long rest.

In addition, the damage from your Shellshock attack counts as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Super Shellshock

At 10th level, when you hit with your Shellshock attack after moving at least 25 feet in a straight line, the target must make a Constitution saving throw against a DC of 8 + your proficiency bonus + your Strength modifier.  If it fails, it is stunned until the beginning of your next turn.  This saving throw is resolved after the Strength saving throw.

Hydro Pump

At 14th level, you awaken your race's ancient connections to the Elemental Plane of Water.  You gain the ability to breathe water and a swimming speed equal to your normal speed.

As an action, you can send forth a powerful burst of water drawn straight from the Elemental Plane of Water in a 30 foot line.  Each creature in the line must make a Constitution saving throw against a DC of 8 + your proficiency bonus + your Constitution modifier.  Creatures that fail take 8d6 + your Barbarian level bludgeoning damage and are knocked prone.  Creatures that succeed take half as much damage and are not knocked prone.

Once you use this feature, you can't use it again until you finish a short or long rest.