How do Black Eclipse and Corrupted Mantle Work?

[(Un)Common Raida]

Black Eclipse/Gore Magala's tyranny is the set bonus for GM's armor for whoever doesn't know.
How does Black Eclipse proc, exactly? Is it just after wailing on a monster for long enough and then you suddenly just do more damage for free for the duration of the fight?
And how does it interact with the corrupted mantle, would it just be even stronger? because this video is pretty nuts
https://www.youtube.com/watch?v=yu8fblm9RgY

[GodEmperor]

Black Eclipse is not a permanent buff during flights, but it might as well be. It procs frenzy onto you the moment you start fighting a monster, and if you're running antivirus 3 (highly recommend for the extra +15% affinity it'll give you once cured), can cure it pretty quickly, giving you the extra damage buff. I believe it lasts for about 45 seconds after curing, and it takes less than 30 seconds for it to reapply frenzy to you again. So it'll have a pretty good up time for the buffs it gives you. And yes, it is cured just by hitting the monster a bunch.
The cursed mantle is a separate thing that can stack on top of the Black Eclipse buff. This is a duo of things I run myself, and it's pretty good imo

[Xaelon]

The frenzy inflicted by Black Eclipse works the same way as Gore's 'normal' frenzy does.

As soon as you enter combat the set bonus inflicts you with frenzy. Then when it goes away, one way or another, you get buffs. Antivirus 3 makes it pretty easy to get rid of too.

The Corrupted Mantle is another source of buffs entirely. While the mantle's effect may resemble frenzy, it's an entirely different thing. As such it stacks.

Which is why pretty much every build runs 2p gore + AV3 and corrupted mantle. It might as well be free attack and affinity.