Twin Link

Death knocks often but having been together all your lives, you and your twin are very skilled at keeping that door shut. 

Two Minds Like One Soul. Though you may not be smarter than others, having two heads is always better than one. Due to your heightened awareness of how your twin's mind works, you have advantage on all insight checks against your twin. You also have advantage on saving throws against being charmed or frightened by your twin. 

A Covered Back. When a blade swings down at your twin, you are quick to attempt to block it. When a creature that you can see attacks your twin within 5 feet of you, you can use your reaction to impose yourself between the two and become the new target.

Hunter Duality. You and your twin are a force to be reckoned with when you both lock onto a chosen foe as your prey. Whenever one twin deals damage to a creature, the other twin can mark that creature and gain advantage on attack rolls against it until the end of the round. If a creature deals damage to one twin, the other twin can, as a bonus action, mark that creature and deal an extra 1d6 damage when making a weapon attack against that marked creature until the end of the round. 

Split Attention. Your keen awareness of each other can be often used to your strengths but also to your detriment. While your twin is unable to defend themself, your concern for your twin's well-being makes it difficult to focus. When your twin is reduced to 0 hit points and begins to make death saving throws, you get disadvantage on all saving throws while your twin is unconscious.