Sentinel

An unstoppable force meeting an immovable object. That's the old story, and nobody represents that better than one who takes the archetype of a Sentinel. When an unstoppable force looms over the world, you are the immovable object that will protect allies, innocents, and that which you care for. The thought of you losing what you protect will make you overcome anything, and your perseverance of defense is something that will make even mighty demon lords think twice about fighting you.

Shrug It Off

Beginning when you choose this archetype at 3rd level, you channel your courage into the ignorance of attacks. As a reaction to damage, you can reduce the damage by your Strength Modifier plus your Constitution Modifier plus your Proficiency Bonus. You can use this ability an amount of times equal to half (rounded up) of your Constitution Modifier.

Improved Protection

Starting at 7th level, you can only see two things to save: yourself, or what you care for. When an ally within half of your movement speed is about to take damage, you can expend a use of Shrug It Off to run in and take some of that allies damage equal to Shrug It Off. The ally takes the remaining damage, you are moved to 5 feet within the ally you choose to protect, you can only move half of your movement speed on your next turn, and you must be wearing at least a shield, medium armor, or heavy armor. 

Inescapable Revenge

At 10th level, you have focused your martial abilities for your goals. You can bypass a creatures resistances to nonmagical bludgeoning, piercing, and slashing damage. You also choose another resistance to bypass at 15th level.

Closing Death's Door

Starting at 15th level, your courage, perseverance, and resolve are almost unparalleled to anything aside from the gods. If you drop to 0 hit points or below 0 hit points, you can drop to 1 hit point instead. When you use this feature, you regain a use of Shrug It Off and cannot use this feature for the next 24 hours.

Remarkable Ignorance

At 18th level, you care little of how close death is, and instead funnel all of your attention to your adversaries. Your Shrug It Off feature doubles your Strength Modifier, Constitution Modifier, and Proficiency Bonus. In addition, you can use the feature equal to your Constitution Modifier.