Laceration question

Grim Dawn Classes, Skills and Builds
1

So maybe this is obvious, but I wanted to be sure:

Laceration says “100 degree arc”. Is this an added 100 degrees to Blade Arc’s 180 degrees (total 280 degrees), or does it narrow Blade Arc’s angle to 100 degrees, or does Laceration’s effect occur separately in an independent (100 degree) area from Blade Arc’s 180 degrees?

I would guess it’s the first option because I imagine it would be hard to squeeze in 8 targets otherwise, but I wanted to check because the tooltip is vague.

2

Adds to the arc. You can see the tooltip for blade arc change when you get it.

3

Thanks for the answer! I was planning builds and not able to test it in game.