Dual Weapon Master

You master fighting with two weapons, gaining the following benefits:

• Whenever you roll a 20 on an attack roll or reduce a creature to 0 hitpoints, you can make an additional melee weapon attack. This can be with either your main hand or off hand weapon and you cannot gain more additional attacks than you would normally make.
• When using both your main hand and your off hand weapon to attack the same target, you may reroll your damage dice and choose which result to use.