Ultimate Will (3.5e Feat)
From D&D Wiki
Ultimate Will [General]
+5 to will saves, rolling a natural 1 on a will save is not an automatic failure.
Benefit: You gain an additional +5 to will saves, this bonus stacks with Iron Will and Superior Will for a total of +10 to will saves. You do not automatically fail on a roll of a natural 1 when rolling will saves.