The bond between you and a close sibling is nearly mystical.
Benefit: Choose a single sibling with whom to share this bond. Once per day when you fail a saving throw while your sibling is within 30 feet, you may reroll that saving throw using your sibling’s saving throw modifier. If you and the sibling are twins or otherwise part of a multiple birth, you gain a +2 trait bonus on the rerolled saving throw. Your sibling must be willing to grant you the reroll. If you fail the saving throw, you and your sibling are dazed for 1 round.
Pathfinder Roleplaying Game: Ultimate Campaign. © 2013, Paizo Publishing, LLC; Authors: Jesse Benner, Benjamin Bruck, Jason Bulmahn, Ryan Costello, Adam Daigle, Matt Goetz, Tim Hitchcock, James Jacobs, Ryan Macklin, Colin McComb, Jason Nelson, Richard Pett, Stephen Radney-MacFarland, Patrick Renie, Sean K Reynolds, F. Wesley Schneider, James L. Sutter, Russ Taylor, and Stephen Townshend.