Picking up this ambitious RPG crossover might have changed me forever. This is standard for nearly every sequel that features a levelling system, but Kingdom Hearts has been going on for so long now that there’s always a lore reason as to why Sora is kicked back to being a beginner at the start of each game. For example, in Kingdom Hearts 2, it’s because he’s been sleeping for a whole year to regain his memories, and in Kingdom Hearts 3, it’s because he was briefly dragged into the darkness by Master Xehanort during his Mark of Mastery. With each game in the series coming up with a new reason for Sora to have to go from Level 1 to Level 99 again, we know without a shadow of a doubt that the same thing is going to happen in Kingdom Hearts 4.
Although we’ll have to wait to see more than two minutes of the game (in two years!) to know for sure, fans already have a pretty good theory of how it’s going to happen. In the final stretch of Kingdom Hearts 3, Sora ends up with his body destroyed by the Demon Tide, which causes him to end up in The Final World, which is sort of like the afterlife. As pointed out by Twitter user Key_Cast, Sora has a conversation with Chirithy here about using the Power of Waking to turn back the clock and stop him and his friends from dying.
Chirithy tells Sora that if he does this, he won’t be able to use The Power of Waking and will “lose his powers” which, of course, doesn’t stop him from doing it to save his friends anyway. The end of Kingdom Hearts 3 shows Sora using the Power of Waking one more time to save Kairi, which results in him being sent to Quadratum for Kingdom Hearts 4. This seems to be the inciting event that will cause Sora to start the game with none of the powers that he had in Kingdom Hearts 3, just like Chirithy warned him would happen. Of course, Sora will eventually regain his powers like he does in every Kingdom Hearts, but it seems very likely that this will be the reason given as to why he’s weaker again.