Dual Wielder Master

You have mastered the technique of fighting with more than one weapon and improved that to another level.

Two Weapon Fighting Improved - 3th level

At level 3 your Dual wielding is improved due to your training with more than 1 weapon at the same time. Dual wield can be done with your off hand without spending bonus actions and each extra attack makes you able to attack again with dual wield eg: level 5 extra attack = 2 hit normal + 2 hit dual wield. Dual wield can be done with martial weapons other than heavy or two-handed weapons and you can add your dex or str bonus to the secondary weapon's damage. You draw or stow two one-handed weapons when you would normally be able to draw or stow only one. At level 3 your secondary weapon deals 1d4 damage increasing at levels 7 to 1d6, level 10 1d8, level 15 1d10, level 18 1d12.

Deadly Weapon - 7th level

You've trained so hard with your secondary weapon that you now ignore magic resistances and immunities with your secondary weapon, and you gain +1 AC if you're holding your secondary weapon in your other hand.

Critical Duo - 10th level

When you crit with the main or secondary weapon you can attack 1 more time with that weapon (free action/special). 1 time per weapon and does not trigger on this skill's own crit. And your attack of opportunity is improved by letting you hit with the secondary weapon in the same reaction. At level 15 of this skill your secondary or primary weapon also crits right after the first crit.

Martial Agility - 15th level

You can crit on the 19th or 20th roll and you gain proficiency and advantage on dex saves along with the evasion skill (You can nimbly dodge out of the way of certain area effects, such as a red dragon's fiery breath or a fireball spell. When you are subjected to an effect that allows you to make a Dexterity saving throw to take only half damage, you instead take no damage if you succeed on the saving throw, and only half damage if you fail.)

Master of All Weapons - 18th level

You have transcended your limits with your weapons and now you gain expertise with all types of weapons and all weapons attacks of martial or simple weapons against you are impossible to hit. You can also use your bonus action to attack with your primary weapon and another with your secondary in the same bonus action.