Shadowblight | D4 Necromancer Key Passive

Shadowblight is a Necromancer Key Passive with the following effect (simplified):
Shadow Damage infects enemies with Shadowblight for 2s. You and your minions deal 10% bonus damage to enemies with Shadowblight. Every 10th time an enemy receives Shadow Damage from you or your Minions while they are affected by Shadowblight, they take addtional X [20%] Shadow Damage.

Once you select Shadowblight as your Key Passive, you can't select any other Necromancer 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 Shadowblight

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

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

Shadowblight Core Synergies

TBA: When choosing Shadowblight, 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 Necromancer Class.
• Related Skill Tree Nodes: Shadowblight
• Summary of all D4 Build and Character Customization Systems.