if your playing against bots and your beating them IE you havnt died yet
so say you have 15 kills and he has 0
if he kills you he will have a bigger power increase compared to you killing him...
The higher you oponents PL the more power you get...
if your killing ppl with lower PL then yours you will not get much power...
thats why on most servers you will notices high PL players going around in normal mode whislt the lower players are all transformed...
hope that helps...
But ibelieve this should have been in the newbie section or the help section but i thought you deserved an answer rather than a flame