I know it's being changed from being able to apply on all enemies to players only as it had some absurd effects in dungeons, however, I propose a few different suggestions. The reason for this is because the nerf was overdone, and it's useable for AOE trash clear for monsters in dungeons etc. You've now removed that, and it was a fun set in PvE.

Here are the suggestions.

Suggestion 1:
(5 Pieces): Dealing direct damage causes enemies to become a Plague Carrier, dealing 1000 Disease Damage over 10 seconds and applying the Diseased status effect. If the plague is removed early it explodes and deals 735 Disease Damage to all enemies within 8 meters of the carrier, increasing by 50% per enemy hit and capping at 600% bonus damage against monsters. This effect can occur once every 20 seconds per target, once per attack, and scales off the higher of your Weapon or Spell Damage.

Suggestion 2:
All boss enemies are immune to the effects of the Plaguebreak explosion.

Suggestion 3 (weird one/rework):

(5 Pieces): Dealing direct damage causes a Plague explosion on an enemy that causes all enemies in a 12 meter radius to become a plague carrier for 10 seconds. Plague carriers take xxx(x) Disease Damage every second, increasing by 50% per enemy hit by the initial explosion. If the plague is removed early it explodes and deals xxx(x) Disease Damage to the target. This effect does not stack with itself, can occur once every 20 seconds per target, once per attack, and scales off the higher of your Weapon or Spell Damage.

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