How Yukari ability Works

This explanation is for readers who are still confused about the power of Yukari's [Manipulation of Boundary]. (By the way, Yukari's ability as Boundary Manipulator is up to Tier 1 if you used Death Battle tiering system)

The only Limitation of this Ability is being that Omnipotence makes boundaries that Yukari cannot manipulates.

Now then:

The easiest thing is that Yukari manipulates the [Boundary] that already has an example, by manipulating the [Boundary] of Death/Life basically she has authority over both of them. By Shifting the [Boundary] a person who is in [Boundary of Life] to Become [Boundary of Death] she can grant Instant Death to that person.

She is also capable of manipulating the boundary between able/unable. At first, 'able to do absolutely anything and everything perfectly and limitlessly' (Metapotence) is in the set of things they are unable to do. Yukari can shift the boundary of able/unable to include this in able, putting it into the set of things they are able to do, and granting them Metapotence. This goes for all of the powers (they essentially have Meta Ability Creation/Destruction, as they are capable of making themselves or another able or unable to do absolutely anything by shifting the boundary between them).

She can also create new [boundary] as shown in 'Touhou Project' by creating [Boundary of Fantasy and Reality] she can separate the original world as Reality and the Illusion world as Fantasy. With it, she can create the Land of Fantasy Gensokyo, this is blatantly Reality Warping.

It's even simpler like this:

1. Creating anything Yukari wants by manipulating the boundary between reality and whatever Yukari want to create (Reality Warping)

2. Giving Yukari powers by using the same technique above (Meta-ability Creation)

3. Granting Yukari immortality by removing the boundary between your current age and how long Yukari wants to live for (Age Manipulation)

4. Defying logic by manipulating the boundary between being bound to logic and being unbound to logic (Logic Manipulation)

4. Transmutating an object into anything Yukari wants by manipulating the boundary between what the object exists as and whatever Yukari wants the object to turn into. (Definition manipulation)

Stuff like that. Boundaries define everything, so the capabilities of Boundary Manipulation are pretty much infinite. There's even a boundary between what you can and can't do, which the Yukari can manipulate to her will and therefore remove all limits from herself.