By skyforbes I was watching KPOP demon hunters and realised that the Demon King was only foiled because he engineered all the pieces needed to do so.
Huntrix was disbanded, the hon moon was destroyed, he could've just got to work sucking souls. But instead he organises a massive concert in order to make a grand entrance and absorb every soul at once.
When Rumi arrives, the other hunters are right there to help her, Jinu is present and ready to betray him, and there's a massive crowd that buffs Huntrixs power so they can create the new honmoon and permanently banish him.
Without the huge crowd and her friends, rumi would not have been able to affect everyone enmasse as she did.
What are other examples of this? I thought perhaps in Endgame, Thanos is only defeated because he stops the Avengers sending the gauntlet back in time. Which makes it necessary for Stark to do his thing.