Defender

You learn to protect your allies from the tides of battle, you gain the following benefits:

• Increase your Constitution score by 1, to a maximum of 20.
• When an ally you can see within 5 feet of you is the target of a creature's attack roll, you can use your reaction to leap in between your ally and the enemy as long as you are not prone, grappled, or restrained You move up to 5 feet into your ally's space, and your ally must have an unoccupied space within 5 feet of them that they take during the move. Your ally's movement does not provoke opportunity attacks. This makes you the new target of the triggering attack roll.

Source: Northern Light Compendium