The Tri-State Area!!!!!

I recently found myself faced with a dilemma of my own making. I had decided long ago that Earth-218 would not be home to any characters with the ability to reshape reality (Franklin Richards, Scarlet Witch, Mr. Mxyzptlk, Q, Cosmo and Wanda, or, dare I say it, Phineas and Ferb). There's just one small semi-aquatic egg-laying mammal of action-based problem. 

Perry the Platypus is a already a character who exists there. 

Therefore, it stands to reason that Phineas and Ferb Fletcher and Dr. Doofenschmirtz and their physics-defying, reality-bending inventions also exist.

We're talking about devices that transform tree houses into Battle Mechs, a giant ant farm that leads to giant, super-evolved ants to bizarre "Inators" that turn objects into bread and another that eliminates all musical instruments starting with the letter "B" (banjos, bagpipes, etc) within its area of effect from existence.

So, how do I reconcile the obvious disparity between these characters and my stated intentions for the world? I could say that Perry isn't around but I think that there is a more interesting option available here.

It isn't Phineas or Ferb or Dr. Doofenschmirtz that have these reality-altering powers.

It's the Tri-State Area itself....

The Tri-State Area

At first glance, Danville and the rest of the Tri-State Area appear to be relatively normal. It is a place where anything is possible. If you can dream it, do it, build it, or make it, you can take it to the limit before the sun goes down and you'd be surprised at what drops out of the sky.

The Tri-State Area has the following traits:

• Normal Gravity
• Normal Time - but summer vacation is 104 days long.
• Infinite Size - The Tri-State Area specifically refers to Jefferson County but the Plane encompasses the entirety of its own universe.
• Sentient - The Tri-State Area is vaguely sentient. It has chosen four individuals in the Tri-State Area and will reshape itself to suit their moods and whims at will, as long as certain conditions are met. Other creatures may alter the plane through whatever means they have available to them.
• No Elemental Traits - No one element dominates in Danville; all are in balance as on the Material Plane.
• Minor Positive Dominant - All individuals in the Tri-State Area gain Fast Healing 2 as an Extraordinary ability for as long as they remain here. Even venerable humans show few adverse physical signs of aging, aside from graying hair or needing eyeglasses - being able to compete in contact sports like roller derby will no ill effects. While in the Tri-State Area, characters ignore the aging penalties to physical ability scores.
• Mildly Good-Aligned - Evil creatures in Danville suffer a -2 penalty to all Charisma-based checks.
• Normal Magic - Magic functions normally within Danville. 

Tri-State Area links

The Tri-State Area has soft borders with the Prime Material Plane. Natives are capable of freely crossing from one side to the other, often without noticing. This gives the impression that Danville is within a day's drive of both Mount Rushmore and the Atlantic Ocean. Non-natives reaching the border of the Tri-State Area simply continue traveling on their way without passing over to the other plane. This soft border allows certain effects to pass through to the Material Plane, e.g., a roller coaster built by Phineas and Ferb has its cars come loose, snag themselves on the wings of a passing jetliner, fall onto the Statue of Liberty, and are then flung to Mount Rushmore, and an exceedingly flexible Eiffel Tower and so on.

Tri-State Area Inhabitants

Humans are the primary sentient inhabitants of the Tri-State Area. Several forms of extraterrestrial life do exist - most notably Martians, a species of small sentient beings that speaks solely in a language that takes the form of the word "meap", and the staff and patrons of the Shooting Star Milkshake Bar. There is also a seemingly large number of sentient animals who understand human speech and serve as secret agents for the government. One of the strangest creatures though is a magical, old-timey bathing suit that lives in the Himalayas. 

The Four - There are four people living in the Tri-State Area that the Plane likes for no particular reason. These individuals seem to be able to bend the laws of physics in specific ways. These are Phineas and Ferb Fletcher and Dr. Heinz Doofenschmirtz, all of whom are capable of creating short-lived, reality-defying inventions. The fourth is Milo Murphy, who is beset by constant accidents and disasters. These abilities do extend outside of the Tri-State Area but the changes they induce are temporary, lasting only a few minutes at most.

Movement and Combat

In general, the Tri-State Area functions like the Material Plane with regard to movement and combat. Combat is handled normally as well but the dominant positive energy trait means that even the most serious injuries heal rapidly and actual death is a rare occurrence.

Features of the Tri-State Area 

The Tri-State Area is located at the heart of Jefferson County. Danville, its largest city has a population of 241,000 people. It is surrounded by suburbs and a number of geographical anomalies that defy logic such as a nearby canyon, chasm, and gorge, a mountain, a glacier that can be seen from downtown, and a beach to name but a few. An impenetrable dome, the creation of a Phineas and Ferb-designed escape tower gone mad, completely encases the entire galaxy.