[Trachmyr]

Instead of adding more levels, how about adding diffrent types:

Cloak: Protects vs. Active/Passive and somewhat vs. Grav
Chameleon: Protects vs. Passive and partly vs. Active.
Temporal Statis Field: Protects vs. all but Grav
ect.

And modify the sensors a bit, make Passive & active smaller for instance.