The thing about Synchronize Abras is that it isn't like you never get repeats, making it a bit more difficult to calculate then people might think. Here's my thought process:

1.) So first of all, there's a 50% chance the Abra you find will have Inner Focus

2.) You can get repeats

3.) In route 2, on the southern area, the chance of finding an Abra is unknown at the moment (we will solve for it later)

Now that we know all this, let's take this one step at a time and solve for 1, which is really easy. The answer is 50%, or 1/2. Number 2 isn't really a problem, so we can just go straight to 3. So in order to find the exact encounter rate of an Abra, we need to find it's "encounter rate" (50%), which isn't Abra's REAL encounter rate, just the chances of finding an Abra if the only Pokemon you could find is an Abra and a Dratini or something. See, percentages are all parts of a whole, so obviously is there's 6 Pokemon with a 50% encounter rate, something's wrong. So, we can sort this out comparatively by using these pieces of information:

- Smeargle has a 2/4 encounter rate
- Drowzee has a 2/4 encounter rate
- Abra has a 2/4 encounter rate
- Meowth-Alola has a 3/4 encounter rate
- Yungoos/Ratatta-Alola has a 2/4 encounter rate (you can find them on different times of day, making it impossible to find both at the same time, so they count as one Pokemon.)

I put their encounter rates as fractions to make it easier to calculate and decrease my chances of making a mistake. From this we can tell that Abra has 1/5.5 chance of being found. (About 15%)

1/5.5 to the power of 25 = 0.00003960212

Then, we cut this number in half because the Abras found may have Inner Focus, which would be 0.00001980106

So there's a 0.00001980106 chance that you will find 25 Synchronize Abras of different natures consecutively.

Assuming it takes you 20 seconds to find a new encounter, we can use the equation 20 x 1980106, because 190106 is statically the number of times you need to find 25 synchronize Abras of different natures.

1980106 x 20 = 39602120 seconds

39602120 divided by 60 = 660035 minutes and 20 seconds (660035.33333333333...)

660035.3333333333333... divided by 60 = 11000.5888833 hours. (About 11,000 hours and 45 minutes)

CONCLUSIONS: So, the chances of you finding 25 synchronize abras in a row, all with different natures = 0.00001980106. In other words, you need to find 1,980,106 Pokemon in order to find 25 synchronize abras of different natures.

The amount of time needed (about) is 11,000 hours and 45 minutes

You might as well SR for a shiny groudon in OR/AS than look for this, and Groudon is shiny locked lmao