I love this topic, so I'm always up for suggestions XD. Thanks for all the new recs~ Thus far I've read Are you alice?, IO, Baroque and Billy bat. For me, Billy bat is winning, its definitely what I was after, I'm addicted XD. IO is also very much what I was after and I'm enjoying it. Baroque wasn't exactly what I was looking for, but it had elements of it, more a mysterious world than a world mystery though. Same with Are you Alice? they're more story related mysteries than a world mystery in a story.

Its difficult to explain...I'll use Bouken eriketetou as an example again. In that she starts living her life normally and then finds out about the floating island and then decides to see what it is. Whereas in Are you Alice? and Baroque the mc is basically an amnesiac husk who is forcefully presented with a mysterious task that only he can do. There are elements of them akin to world mysteries but they aren't open mysteries anyone can attempt to solve, they're problems presented to the main character alone. They were pretty fun reads though. I liked Baroques atmosphere, it really draws you in and the whole things with the previous Alices and regrets was interesting in Are you Alice?

@Millenia_Curse: Elixir has been on my radar and I haven't encountered lega no 13 before, they look interesting and I'll give them a try, thanks ^^

@GracieCrazy08: I am not a fan of Pandora Hearts. I really tried to read it but I just couldn't. I enjoyed it years ago but I grew out of it between when it first came out and when it got popular. Thanks for the suggestion though~

@anngeelah: I've already completed Fullmetal alchemist, enjoyed it lots. Also I have yet to read Zetsuen no tempest, so I'll try it thanks~