Thunderous Conversion

Thunderous Conversion is a passive feature that disorients the user's target whenever they deal thunder, lightning or radiant damage.

Description

When the wearer deals ⁠Thunder, ⁠Lightning, or ⁠Radiant damage, inflict 2 turns of  Reverberation upon the target(s).

 Recharge: Per attack

 Reverberation

Duration: 2 turns

Affected entity has a -1 penalty to Strength, Dexterity, and Constitution  Saving throws per remaining turn.

When the entity has 5 or more turns of Reverberation, it takes 1d4⁠⁠Thunder damage and must succeed a DC 10  Constitution saving throw or fall  Prone. The condition is removed afterward.

Granted by the equipment:

The ⁠Lightning damage originating from Lightning Charges doesn't seem to trigger the item and thus doesn't apply  Reverberation effect to targets unless on Honour difficulty rules. The ⁠Radiant from Morninglord's Radiance, however, does trigger Reverberation - both on weapon and spell attacks.(as of 4.1.1.3648072)
The ⁠Thunder damage from  Phalar Aluve: Shriek does not activate Thunderous Conversion unless on Honour difficulty rules.
If the wearer's attack adds a 5th stack of Reverberation, the resulting Thunder damage re-applies two more stacks of Reverberation.

Though stated "upon the target(s)", Thunderous Conversion can only trigger once per attack.
- This means that AoE spells (e.g.  Radiance of the Dawn or  Flame Strike) can only apply  Reverberation to the first target in the log order, leaving the rest without the effect.
- This also means that dealing multiple instances of damage in a single attack (e.g. with  Lightning Arrow) will still only apply 2 turns of  Reverberation.