Northman Rage

In the heat of battle you occasionally enter an uncontrollable rage, unleashing the berserk fighting style of your homeland. 
When you or one of your allies within 30ft of you are subject to a Critical Hit, you must make a Wisdom saving throw DC10 or half the damage taken, whichever is higher.  On a fail your Northman Rage is triggered.  You can opt to automatically fail this save.  This rage can only be triggered once per short or long rest.

While raging, you gain the following benefits if you aren’t wearing heavy armor:

• You have advantage on Strength checks and Strength saving throws.
• When you make a melee weapon attack, you gain a +2 damage bonus.
• You have resistance to bludgeoning, piercing, and slashing damage.

If you are able to cast spells, you can’t cast them or concentrate on them while raging.

Your rage lasts for 1 minute. It ends early if you are knocked unconscious or if your turn ends and you haven’t attacked a hostile creature since your last turn, or taken damage since then. You can also end your rage on your turn as a bonus action.