Spear Dancing Style (Combat, Style)Source Weapon Master's Handbook pg. 17
You can use polearms and spears as double weapons.
Prerequisites: Dex 13, Two-Weapon Fighting, Weapon Focus with the chosen weapon.
Benefit: Choose one weapon from the polearm or spear fighter weapon groups. While using this style, you grant the chosen weapon the double special weapon feature, using the weapon’s normal statistics for its main-hand end and the statistics of a light mace for its off-hand end. A weapon wielded in this way loses the brace and reach special weapon features.
Special: A character with the weapon training (polearms or spears) class feature can use Spear Dancing Style with any polearm or spear, respectively, in addition to the chosen weapon.