Source: Unearthed Arcana 81 - Heroes of Krynn

Prerequisite: 4th Level, Squire of Solamnia Feat

You are a Knight of Solamnia aligned with the Order of the Sword, a group devoted to heroism and courage. Bravery steels your spirit, granting you these benefits:

• Disciplined Spirit. You gain proficiency in Intelligence, Wisdom, or Charisma saving throws (your choice when you take this feat).

• Willpower. Immediately after you or a creature you can see within 30 feet of you fail an Intelligence, Wisdom, or Charisma saving throw, you can expend a Hit Die. The saving throw increases by an amount equal to a roll of that Hit Die, potentially turning a failure into a success. Once you turn a failed saving throw into a successful one using this feat, you can’t do so again until you finish a long rest.