Reckless: While in a rage Rutgar may choose to attack recklessly to gain advantage on melee attacks, but all attack rolls against him are made with advantage.

Great weapon Master:

• On his turn, when he scores a critical hit with a melee weapon or reduce a creature to 0 hit points with one, he can make one melee weapon attack as a bonus action.
• Before he makes a melee attack with a heavy weapon that he is proficient with, he can choose to take a -5 penalty to the attack roll. If the attack hits, he adds +10 to the attack's damage.

While Raging Rutgar gains a +2 increase to his damage rolls.