Posting this here from suggestion here from my earlier post in the
Imp. Whirlwind discussion.
Reg:
Intelligence 13
Dexterity 13 (or at least something not so high)
BAB +15 (the first BAB in the line. +15 or +20)
21st level
Dodge
Expertise
Mobility
Spring Attack
Whirlwind Attack
Specifics: The character performs two full attack actions, rolling two melee attacks at the full base attack modifier against all opponents within 5 feet. (or 10)
By Imp this allows them to strike all around twice instead of just once like normal Whirlwind. Though not sure if adding the second strike to the feat could be done.