You no longer have disadvantage on ranged attacks within melee range of enemy creatures.
You can wield the Lightning Shotblaster with one hand, but you cannot have one in each hand.
You can wield a Lightning Revolver in one hand and one non-two-handed weapon in the other. Burst Fire no longer results in you landing prone.
For Firearms you have a Weapon Mastery for, you may instead use Strength for ranged weapon attacks with that weapon.
When making an an attack using a two-handed melee weapon, you can expend a superiority die to leap 10 feet without provoking opportunity attacks and make a melee attack against a creature within range. On a hit, add your superiority die to the damage roll.
When making an attack using a one-handed or versatile melee weapon, you can expend a superiority die to make a melee attack against all creatures within 5 feet of you. You are not allowed to forgo attacks against certain creatures.
When making an attack with a ranged weapon, you can expend a superiority die to add extra range to your weapon. You ignore the disadvantage from the weapon's long range, and you add your superiority die to the damage roll on hit. All creatures within 5ft of the target on a hit also take the superiority die's damage.
When making a melee attack, you can expend a superiority die to thrust your weapon into a creature. This attack ignores the creature's shield if it has one, deals piercing damage, and you add your superiority die to the damage roll on a hit.
When making a melee attack with a weapon that deals slashing damage, you can expend a superiority die to make a second attack with the same weapon.