@Tecknokid123 Princess has been slowly uncovering a plot by her fiancée to blackmail her into giving up her body to the cult for research into the royal blood and it's connection to the Diabolos curse. She tried to thwart this plan, but he held the king hostage, and she didn't have the strength to succeed. If she refused to do what he wanted, he would start a war, so she was going to give herself over to save her kingdom. The plot twist is that he was apparently going to start a war anyway. Cid, not understanding any of this, did some chunni posturing and offered her the power to seize her own destiny, which was the power boost ball of mana from a chapter or two ago. She accepted, and decided to change her fate. Her choice was to assassinate her own father to stop the blackmail from working and ruin the cult's plans to start a war.
This has been slowly explained over the last ten or so chapters, as a sort of background plot that's been unraveling. Cid stumbled into this accidentally, because that's how he ALWAYS gets involved, and accidentally ruined the whole plan by submitting himself into the tournament as the mysterious stranger. Neither the other princess or the prodigy were supposed to lose their fights, but he beat both of them. Cid already had his own plans for how to dramatically finish the tournament off like a proper tournament arc in a manga should be done, but when the princess assassinated her own father, he immediately abandoned them all and revealed himself, because as a Master Class Ham, he realized that nothing he was thinking about would be able to top whatever the fuck just happened in front of him, so fuck it, we're doing it live, then.
