The themes of any book are limited to our imagination, soo.... they are infinite. Since this ''BoI'' can become a giant with infinite numbers of Ideas etc..., I thought that the best way for this work would be me choosing the most liked Theme in the comments.
================================================================
For example: DC, and writing about the Protagonist we would like to see, if he would be a Hero like Batman, Robin, Green Lantern.... Or even Villans like Lex Luthor, Joker , Brainiac.... Even totaly new like Transmigrator/Rebirth ( can be hero/villain/anti-hero...) ( With system or not ) ( With Others universe elements like cultivation, ability....) and the lore/story is up to the author, since the objective of this book is helping the first step for the beggining of a new story, not others things.
================================================================
Another thing is do not comment thing like X theme with system, with Other universe elements etc...
I already considered this and in the END of the chapter i will put in every single one of them in this exacly way:
================================================================
With system or not, With Others universe elements like cultivation, ability, skills, bloodline, heck even pokemon, With Multiverse ( Like goes to another universe with no relation to the original ) is up to the author to decide, feel free to choose it or not :D
===============================================================