If you asked who the worst Supreme Kai in all the Zeno universes was, everyone would say it was Shin, the Supreme Kai of Universe 7—and in fact, they would be right.
Supreme Kai Shin had been transferred over full-time from Apprentice Supreme Kai after the previous Supreme Kai, Oul, died unexpectedly. Because he had lacked formal Supreme Kai training, his way of handling things was still like that of an Apprentice Supreme Kai. Whether in knowledge or perspective, he could not compare to the other Supreme Kais.
That was why, for major gatherings like the Zeno Conference, Beerus, the God of Destruction, and Whis were unwilling to bring him along.
The reason Beerus looked down on Supreme Kai Shin was not that he was weak. After all, a Supreme Kai was not a battle god; in terms of power, they were inherently on the lower end of the Godly Sequence, so one could not be too demanding.
Their task was to bestow vitality upon each planet and maintain the vigor of the universe's creation.
What truly angered Beerus was Supreme Kai Shin's lack of ambition. A mere Majin Buu had become his nightmare... Every time Beerus saw him acting timid and submissive, without the slightest dignity of a god, he wanted nothing more than to slap him dead.
Because he almost never left the Supreme Kai World, the very existence of the Supreme Kai had been reduced to a legend in the lower realm. This was unique across all universes. If the other universes found out, Universe 7 would lose all face.
What did Majin Buu wreaking havoc across the universe have to do with the Supreme Kai? If anyone was supposed to destroy him, that was the God of Destruction's job.
A Supreme Kai not creating life, but