You pretty much answered your own question right there lol he most certainly wasn’t like this in the first place until he found out a certain chain of events that might lead up to his downfall. This is the reason why he committed the genocide against the MC’s race and destroyed the home planet with his own hands. His army didn’t do anything aside from blocking off all access off the planet but fortunately your mother was able to find one that they didn’t notice. Yes, Lord Kann is powerful enough to literally destroy a planet by himself so it’s quite a rare event that you would ever see him physically fight.
cough K’Yors cough
Finally! Someone noticed the Easter eggs!