Um...

"Increased assault distance in ranged attacks"
"Increased assault angle in ranged attacks"

I just noticed this on my Brionac. What the heck does it mean though?

No, it is not reforged, but I did use it to SoG Cromm Cruiach.

Splash. Angle and damage i think? Unless it says that now ingame?

I believe these are the 2 blue lines of text that appear on the Brionac when you equip it while in Demigod mode. I think it increases the range and the explosion radius of Spear of Light.

“	When using the Shock and Awakening of Light Skills, the Splash Range and Splash Radius of Brionac increases considerably.	„

I think its referring to this part.