Bring back custom story chapter teams

[hybrid zephyr]

pls kuro

[versed anvil]

I think they somewhat do that in Bambinata's patch but it's limited to the character locked, so you get to use your own character or the "trial" one.
But honestly I don't really miss custom teams for the later chapters, it can break immersion and there's also the fact that the battle nodes are also used to showcase the new character