@Merilirem - indeed. I liked Negima's idea that it's perfectly possible for the MC to win against an AEGIS cruiser which has twice as much "power" if he plays his cards right.
(also Negima is the only manga I've seen that gives a unit of power measurement. In this case, it's an ordinary schoolgirl that was standing nearby)
Some things don't make sense. Why would someone return an object to the demon lord to restore her power, 5 years after trying to kill her? Why do engaged couples have to duel to cancel their engagement? Seems kind of pointless.