Two-weapon proficiency: You are capable of making attacks with your offhand weapon as a bonus action. This attack can only be used once per round and it will gain a -2 penalty in attack rolls. At rank III you will have no penalty attacking with your offhand weapon.
Combat style: You gain a number of additional attributes depending on your offhand weapon. Every time you raise your rank in two-weapon fighting you receive a number of attributes according to its type, as is specified below:
Dual block: Once per round you can do an additional parry with your offhand to block a particularly dangerous attack. This ability lets you do an additional parry against an attack which you have blocked unsuccessfully (the penalty from your offhand weapon will still apply). This ability can be used an additional time per round at rank III.
Two-weapon rend: Your second attack is even stronger against vulnerable targets. Whenever you hit the same target with both weapons in the same round your offhand weapon will deal +1d6 damage.
Circular cleave: When you use Great cleave you can also attack with your secondary weapon. A cleave done this way will add a -2 penalty to attack rolls but you will be able to target all creatures in a 5 foot radius. Distinctly from cleave, if a character successfully blocks with a shield it will not stop this effect, but you will be prevented from targeting creatures adjacent to it with this effect.
Greater disarm: Instead of attacking you can use your offhand weapon to do a disarm maneuver as a bonus action against a creature which attempts to parry your attack. Also, creatures with a trapped blade are unable to parry attacks made with your offhand weapon.
Death by a thousand cuts: Whenever you use Steel whirlwind you will gain an additional bonus to damage equal to the base damage of your offhand damage and you will increase the level of all permanent injuries you inflict by one step. You are also able to attack with your offhand weapon an additional time per turn.
Dual block: Once per round you can do an additional parry with your offhand to block a particularly dangerous attack. This ability lets you do an additional parry against an attack which you have blocked unsuccessfully (the penalty from your offhand weapon will still apply). This ability can be used an additional time per round at rank III.
Dirty fighting: Your offhand weapon will add 1d6 to attack rolls and gain sneak attack modifiers whenever it strikes a target damaged by your main weapon. You will not gain benefits from this ability if you are disarmed from your main weapon or your target has greater uncanny dodge.
Trap weapon: Using your two weapons you are capable of catching swords bigger than your own. This ability lets you spend your main and offhand attack to attempt to trap your enemy’s weapon, as is specified in slashing blades. If you have trapped your target’s blade you will not be able to feint unless you have the ability greater feint.
Targeted attacks: All penalties gained by targeting vulnerable parts of your target’s body will be reduced by 2 when attacking with your offhand weapon. Instead of attacking you can use your offhand weapon to feint a target.
Deadly slice: As a standard action you can make an attack with both weapons on a specific point of your opponent’s body. Using this ability will require you to spend one of your attacks with your offhand weapon in exchange of increasing your base damage by a value equal to your offhand weapon’s base damage and increasing the level of all permanent injuries you inflict by one step. You can use your offhand weapon to attack or do maneuvers an additional time per round
Weaken defenses: You can shoot with your secondary weapon to expose your target to other attacks. You gain advantage in bullet tricks made with your secondary weapon and whenever you hit an enemy with it all subsequent attacks you make against the same target will receive advantage as well.
Cover Shots: You are able to create cover fire with your secondary weapon to protect yourself from attacks. When using this ability you will receive disadvantage on all your attacks made with your secondary weapon, but you will be able to use your firearms to protect yourself from attacks, adding your attack bonus to defensive rolls. Using this ability will consume an additional bullet per turn.
Rain of lead: You can fire multiple shots at once to attack a large group of enemies. This ability allows you to concentrate numerous attacks into one, increasing the area of effect by 5 feet and the base damage by 2 for each attack used in this manner. Attacks made with lead rain will count as area attacks, dealing half damage against enemies that manage to defend themselves successfully against your attack.
Predict movement: You have a supernatural instinct for danger. You receive the uncanny dodge ability (improved uncanny dodge if you already have it) and upon receiving a surprise attack you can make an attack of opportunity with your secondary weapon as a reaction. Your firearm attributes will also apply to this attack.
Master gunslinger: When attacking a creature that has suffered damage at some point in the round you will increase your base damage by 1d6. Reloading your secondary weapon costs you a move action and you do not need to have a free hand to do so.