(Video) 'Melee Charge' deals 20% bonus damage to Mid Boss every attack without its 16 second cooldown.

[SardineS]

As the name implies, Heavy Meleeing the Mid Boss with 'Melee Charge' item deals bonus 20% damage every time without being put on cooldown.
View attachment 2024-10-24 11-44-28.mp4

This second clip is what alerted me that the math might be off, when Shiv quickly soloed the mid boss by punching it to death at 20 minutes.