Blade of Infinite Edge (Ex): For a number of rounds equal to her HD, a Vorpal Warrior grants any slashing weapon that she wields the vorpal quality. She can add or remove the vorpal ability as a free action, but the ability itself must be used in minimum of one round increments. If any slashing weapon she wields already has the vorpal quality from another source, upon a roll of natural 19 or higher, she can decapitate a foe with it.
The Heads Will Roll (Ex): At ninth level, upon a roll of natural 18 or higher, a vorpal warrior may decapitate a foe when using any vorpal weapon. This can be used with the vorpal strike feat from Epic Level Handbook.
This should be pretty explicit. I moved the sentences around for clarity.
Yeah, this seems pretty clear thanks for the wording help. Do you guys think that I should add a recovery mechanic for getting back rounds of infinite edge?