So, in the WN, and likely in the LN/manga, the main bad guy of the entire story is Medea, a goddess who wants as much power as possible. Instead of going the simple route of just destroying a universe and taking the power from it, she enjoys games... in this case, she enjoys making people betray each other via her shards who will manipulate people. An example of such a shard is Malty. If I recall correctly, she was also one person who contributed to the 4 chosen weapons in the form of the cursed series, making sure she can destroy the heroes if she is able to build enough self-doubt in said heroes. She is also the reason why Glass's world is so fucked up too. The 'chosen heroes' use the world like an RTS game.
So... based on the fact she manipulates people this extremely over multiple dimensions, I wouldn't be surprised if she fucked about with the hero ritual so she can have easier people to break.