It says to declare an area of up 1000 cubic feet. I'm no expert at math, but isn't that just a "10 foot cube"?
A cubic foot is defined as "the volume of a cube with sides of one foot in length", meaning 1ft x 1ft x 1ft = 1 cu ft
10ft x 10ft x 10ft = 1000 cu ft
Am I mathing this wrong? Does the Sentinel Fusion only cover a 10 foot cube?
Level 3 isn't very high for a fusion.
Agreed. It's also a lot more powerful on ranged weapons, as you have to be in the area, not the target. A sniper can recieve a pretty substantial benefit from it without much worry.*
EDIT: Self correction. It's a bonus to Initiative and Perception. It's intended for standing guard, doesn't need to be a large area. Though Perception to help track hidden targets while sniping is still helpful.
In game terms, this is good enough to cover you and your melee buddy next to you, as well as your other two buddies with either ranged or reach weapons standing right behind you. On a grid, it's basically a 2 square radius from any give junction.
I think, for a lvl 3 fusion, that's actually pretty good. Better than just the wielder anyway since it can give all or most of your party an advantage rather than just you.