Master of Rage

You have honed your ability to control your thoughts while raging, learning techniques that grant you the following benefits:

• You may attempt to cast a spell. When attempting to cast a spell while raging you must make a Wisdom, Intelligence, or Charisma (depending on your spell casting ability) saving throw (DC 10+spell level) if successful, the spell is cast as normal. On a failure, you are unable to cast a spell this turn and you lose the corresponding spell slot. (you do not lose the action or bonus action unless the spell is successful)
• You gain the ability to maintain concentration on a spell that was cast before entering rage.
• While raging, you have advantage on Constitution saving throws that you make to maintain your concentration on a spell when you take damage.
• You can perform the somatic components of spells even when you have weapons or a shield in one or both hands.