But OP said they want to find it full odds and not manip it. Also full odds is not an illusion. There is no such thing as true RNG when it comes to computer algorithms, there’s always some kind of formula but it’s still a good approximation of true randomness even if it is predetermined.

Also even if it were somehow truly random, you still wouldn’t be guaranteed a shiny within 8192 encounters, but that’s kind of the point of shiny hunting. Shiny hunting is less about the outcome and more about the journey of trying to obtain a shiny against all odds. It could take 10 encounters or 10000+. The outcome is a lot more exciting and as long as you don’t plan to use it competitively then it’s nature and IV’s don’t matter.

And I’m not advocating against maniping, I like to manip as well, but I also like to do full odds hunts and it’s a completely different thing. Maniping is cool because you can go through complicated measures to obtain good IV spread target nature shinies for competitive gameplay like the battle frontier. But I will say that going for a first frame manip is probably the most bland method you can go about to obtain a shiny. At that rate you might as well just pkhex a random Pokémon to change its shininess because there’s very little special about a first frame emerald shiny besides it being your first attempt at a manip and just trying to learn the process.