Heighten Turning

Extra Turning (PH) , CHA 13,

When you turn or rebuke undead, you may choose a number no higher than your cleric level. Add that number to your turning check, while subtracting it from your turning damage roll. If you're not a cleric, you may choose a number no higher than your effective cleric level (for instance, a paladin could choose a number up to two less than his paladin level). If a prestige class increases your effective turning level, use your effective turning level.

When you turn or rebuke undead, you may choose a number no higher than your cleric level. Add that number to your turning check, while subtracting it from your turning damage roll. If you’re not a cleric, you may choose a number no higher than your effective cleric level (for instance, a paladin could choose a number up to two less than his paladin level). If a prestige class increases your effective turning level, use your effective turning level.

You can affect more powerful undead with your turning or rebuking attempts.