My theory is that Maribel doesn't become Yukari nor is she already her, I think that they live in parallel universes and are interconnected by their ability to see boundaries (and as Maribel's ability further evolves, manipulate them as well). Maribel might turn into a youkai but I believe that she will still be a human with Yukari's power and manage to consciously traverse the Hakurei barrier together with Renko and enter Gensoukyou.

For me, I don't believe that Maribel is Yukari or on progress of becoming like Yukari. Granted, while their abilities may be similar in nature, I like to believe that they are different people, since I don't really think that Maribel and Yukari are the same people, since Yukari is a lazy bum of a youkai. (Ironically, I haven't read any CD stories besides Dolls in Pseudo Paradise; just it seems unlikely that they are basically the same person or related.
  )

>they look the same but at different age
>they have the same powers but Maribel just starts discovering them
>when asked about them ZUN made reference to Lafcadio Hearn, who changed his name to Koizumi Yakumo
>fans: "meh, could be a coincidence"

Like, c'mon, ZUN's reputation of a "trolling creator" is grossly overexaggerated. Theories are fun and all, but that just takes away mystery and adds nothing in return.

Taboo Japan Disentanglement is out.

Yup, once again, nothing happened.

I am  sincerely sorry if voting "trolling" and its meaning were felt off in its worst light, since in this case I understood and converted "trolling" similarly to "good-natured and thought-out clues, insights, build-up(s), lead-push-on(s)"

There is quite likely some or enough facets of The Truth to all of you all quoted insightful statements written here, or otherwise implied or linked through.

As I have written in my apology earlier, by my humble opinion I have voted the 3rd "...not Related and ZUN(Jun'ya Ota)is..." ... even if it the last "Other..." has its own good merits , plus enlightening insights by you all by now , for an alt. vote.

My choosing of the 3rd option is motivated by obedience to canonical clues and proofs - I am sorry ,again, if these CAPS here are misunderstood ,but they are justly here for highlight-reading-aid -  ( Sakuya Izayoi's BEYOND-HUMAN-LIKE/NON-HUMAN-LIKE/YOUKAI-LIKE ability/power/talent/capabilities" to "Manipulate Time") ; "...even though is very rare for humans(ref.+hint the prime example is Sakuya Izayoi ,but it strongly hints to Reimu,Marisa,eventual etc.as well)to hold and develop such powers/capabilities(ref.+hint of the calibur BEYOND-HUMAN-LIKE/NON-HUMAN-LIKE/YOUKAI-LIKE) it still possible to..."(ref.+hint that they are deemed HUMANS but also MOSTLY BEYOND-HUMAN-LIKE/NON-HUMAN-LIKE/YOUKAI-LIKE but POINT-AND-BORDERS-OF-CONTACTS BETWEEN THE 2 NATURES are wondered and not fully dismissed mainly ref. to with Sakuya Izayoi. ) ..."
.My possible alternative vote for the Last Option are according  to reasons and justifications I have just written between (...) especially the repeatedly CAPS ones.   

I am trying to explain and share that "being Truly Related Somehow" would "bear more justification and purpose, deeper and more founded " than the justly and truthfully present and pointed out "faithful number of 'Bordering' and Indirect Similarities and Proximities" including "Talents ,Powers,Appearance from the present to the future to eventualities"

Please do tell when you're sure about it! I've been craving for more thoughts about the album as we're only listening to 1 track per day with friends (except on weekends)

> Take a moment to dwell on how we feel weird, trying to pinpoint what exactly is different.

> Well, it feels like your wrist, but that's probably because of the ribbon itself...
> Unlike the other recent times, you don't feel anything off about your swords this time, either.
> "Let's put her on the bottom of the list for now." Miko says. "The sooner she gets wind of this, the more we'll have to deal with her, regardless of if she's the culprit or not."
>_

Probably HRTP, though I've never played it. It just doesn't seem like that good of a time.

Aww, c'mon..! It is fun, addicting and absolutely didn't destroy me mentally (ᵔ◡ᵔ).

> "An excellent idea..."
> Locate ice fairy in question and challenge her to a duel!