Expanded Mastery: 10. Every time you inflict at least 15 points of damage with a melee attack, you gain one cleave token. You can spend 3 such tokens in order to gain an additional melee attack. You make this additional attack at the same attack bonus as the last attack you made before spending the tokens. You may attack any creature in range (not just the one you attacked). You lose all accumulated tokens at the end of your action.

Note: if you also have Cleave Expanded Mastery 8, the tokens you earn from that feat can also be spent to generate more cleave attacks. Likewise, the tokens gained from this feat can be spent to gain additional damage.