Barbarian Primal Path of the Killer

Those barbarians that follow the primal path of the killer excel in one activity above all others. Can you guess what it is? Terrifying, methodical, these barbarians isolate a foe in combat, crashing into them and putting them on the ground. A killer does not relent, attacking their downed foes again and again with terrifying, crushing blows. A killer cannot be turned away from their quarry: deadly blows skitter across their skin, finding only glancing purchase. A killer cannot be escaped, and does not stop once the hunt begins. A killer can only be faced head-on, and those that do quickly find that a killer excels in one activity - above all others.

Crushing Blows At 3rd level, your rage transforms you into a deadly killer. You put your foes onto the ground, then slaughter them while they plead. While you're raging, the first time you hit a creature with a melee weapon attack on each of your turns, if it is no more than one size larger than you, it must make a STR saving throw (DC = 8 + your proficiency modifier + your STR modifier) or be knocked prone. When you knock a creature prone with this feature, it is frightened of you until the end of its next turn.

One Scary Motherfucker When you choose this archetype at 3rd level, you gain proficiency in the Intimidation skill if you don't already have it. Your proficiency bonus is doubled for any ability check you make that uses that proficiency.

Unstoppable Force At 6th level, you are implacable foe - when your enemy thinks it's over, you get back up and show them who's in control. While you are raging, when you take a critical hit, you may use your reaction to turn it into a regular hit. If the source of the attack is within your reach, you may attempt to shove it prone as part of the reaction.

No Escape At 10th level, creatures you've knocked prone with Crushing Blows leave a trail of spattered blood on the ground. You have advantage on Wisdom (Survival) checks made to track them and Wisdom (Perception) checks made to spot them while they hide. The bleeding stops when the creature receives magical healing or uses a medicine kit to bind their wound. Otherwise, the creature bleeds for one hour. Also at 10th level, you are a hunter of singular purpose: you no longer need to eat, drink, or sleep, and you have advantage on saving throws made to avoid exhaustion.