Walking Arsenal | D4 Barbarian Key Passive

Walking Arsenal is a Barbarian Key Passive with the following effect (simplified):
Dealing any damage with one of your Arsenal weapon sets grants you 10% increased damage for 6s. While all three bonuses (for each Arsenal set) is active, you gain an additional 15% increased damage.

Once you select Walking Arsenal as your Key Passive, you can't select any other Barbarian Key Passive. They're considered to be very important parts of your build, so it merits quite a bit of possible discussion.

How best to use Walking Arsenal

Basically this segment will be giving you a rundown on the basics on the "WHEN, HOW, and WHY" of the Walking Arsenal Key Passive.

Questions we would answer here would be like:
How to use Walking Arsenal, as a baseline.
Why you would choose Walking Arsenal over other Key Passives.
When would you consider Walking Arsenal? As a build-around? An "augmentation"?

Walking Arsenal Core Synergies

TBA: When choosing Walking Arsenal, are there "absolute godtier" level synergies you essentially NEED to take?

Related Links & Other Information

Still got a lot to do, a lot of data to track, and how best to present it! Post-launch will clarify alot of this for us!

In the meantime, Related Links:

• If you're here, you're probably looking for some info on the Barbarian Class.
• Related Skill Tree Nodes: Walking Arsenal
• Summary of all D4 Build and Character Customization Systems.