[@Herald]If you read the rules correctly, they can have 1 power.

But I would prefer if only around 2 of the Hybrids had powers...the others would just rely on their other Hybrid abilities.

They can switch it on and off for periods of time, if they kill...don't want to feel regret/guilt/emotions...but they can always switch it back on. It doesn't get affected in Hybrid Form...it stays the same.
In the character sheet, state how their humanity is at the current time...it can change as the rp progress...if it's switched on...it can get switched off later on,