[@TheMinorFall]The pact is standard throughout, but each Knight would be granted a different power, based on their own strengths and personality and all that.

[@Bourgeoisie]Let's say a normal Knight would be powerful enough to take down a fairly strong adult, slightly faster than an average person, and be able to jump to like a low rooftop and such. (We regard gravity as a piddly little detail, and mostly leave it to the Muggles.)
In comparison, a Berserker Knight is like the human tank, laugh-in-the-face-of-steel-doors-promptly-before-punching-it-in-with-two-hits Knight, who's capable of keeping pace with cars for a little while and for whom gravity is more of a suggestion than a law when it comes to jumping.
Essentially, you have:
Knocking down a person vs knocking down doors (and maybe walls),
Slightly above-average speed vs pretty abnormal running speed,
Jumping a story or two vs jumping several stories,
And decent endurance vs huge stamina reserves.

Obviously, this will need to be balanced properly inside of the RP, but hopefully it won't be much of an issue.