Enduring Ki

(Complete Scoundrel, page 77, DnD 3.5)

[General]

You can channel inner energy to make your ki powers last longer.

Benefit

By spending an extra daily use of your ki power when you activate it, the chosen effect lasts for an additional round (ki power is a class feature of the ninja; see the sidebar for details). You also gain one extra daily use of your ki power.