It adds an additional 100+ Base Damage and causes Flame/Shock Damage. Personally I love the Volatile Hunter Blueprint however it's from an additional DLC that I purchased. Two-Handed Weapons such as Maces and Axes work well with the Whirlwind Ability and can clear out a Horde of zombies that might have gathered underneath you. Boosting Damage and Speed will only improve the performance with that particular weapon. Skilled players that can utilize various of the Power Abilities while mixing in Dodges and Grapples might use Short Swords, Machetes or Katanas for decent mid-range and speed rating. It will vary greatly and it also depends upon your play-style too.