Multiple War Raptors on a Base
I assume you mean the "War Raptor" (The original text was "Rapture").

The War Raptor text:


  Ongoing: Gains +1 power for each War Raptor on this base (including this one).


This means, that each War Raptor gives a +1 bonus to power on each other War Raptor on the same base. The power of each War Raptor is 2 + the total number of War Raptors on the base.


One War Raptor give 2+1 = 3 power
Two War Raptors give 2 times (2+2) = 8 power
Three War Raptors give 3 times (2+3) = 15 power
Four War Raptors give 4 times (2+4) = 24 power


This is a hint that a single raptor is weak, but they become deadly while fighting in packs.