You get a bunch of weapons, hit people with them. 

Super blah

Much super blah

One and Done

An Arms Master is blah blah

Starting at third level whenever you make a weapon attack with a weapon you haven’t attacked with since your last long rest you deal an additional 2 damage of that weapons damage type.

Living Armory

At 3rd Level you become a walking armory. You gain the following benefits:

• The weight of all weapons you carry and wield are halved. 
• When you attack with a weapon, you can stow anything in any or both of your hands and draw that weapon as part of the attack. 

Arcane Arms

Starting at seventh level your mastery of weapons is no longer bound to mundane arms. As long as you are attuned to a magical weapon all of your weapon attacks count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage. In addition you learn the identify spell, and can cast it as a ritual, but only for magical weapons. 

Unconventional Tactics

Something descriptive. As a bonus action you can choose a following weapon Property; Finesse, Light, Reach, or Thrown. Until the End of your turn all of your weapons are treated as having the chosen weapon ability in addition to any abilities they may have. You can use this feature three times, and you regain all expended uses of it when you finish a long rest.

Much blah

much blah