Deep down I know that is true but we should not be blind enough to ignore the fact that this is a family manga made to give you the floofs rather than a complete shounen.
If it wants to give me the floofs, it shouldn't dedicate a whole arc to painting one asshole as the big villain who's done irredeemable shit only to let him off with a few slaps. That's just gonna piss people off more when the conclusion isn't satisfactory. It could've went the route of sister tries to assassinate, is defeated and slowly brought back to her brother, king is pissed, sends some more, fails, is confronted, given the business and then return to status quo with the sister added to the family.
The king going all out like this and doing all the shit that he's done should result in an equally strong opposite reaction, like he coulda been punched twice while he was still in that mana monster thing, and it goes haywire and overloaded and explodes, disintegrating the king along with it if you want a "non-violent"/ambiguous end to him without explicitly stating it, and labeling him as "disappeared" and have his son/daughter take over instead.
The author could have opted for less vilifying approaches or better conclusions, but went with the cliche way, as always..
