Nearly a year ago CengizMan gave us a very complicated and very detailed "Pokemon Transfer Guide," which sought to educate the public on how to carry over their creatures from game to game.
With Pokemon Sword and Shield as the new generational be-all-end-all (minus some National 'Dex characters here and there), some folks were on a mission to transfer every possible 'mon, and by God, that little graph helped them do it. But with new options in the mix CengizMan has tweaked their guide a bit (beyond the last update a few months ago) to account for new transfer methodologies.
So what are the new updates? Well, Generation I and II transfer possibilities have been added, as well as Pokewalker, Dream World and Poke Ball Plus functionality. The legend is going to be very helpful for newer players when identifying this massive chart, and naturally, Pokemon Home is imperative to the process now.
As a note, CengizMan clarifies that Pokemon Go -> Home transfer mechanics are not live at the time this chart was posted, but they are coming, so it was added as a future-proofing choice.
Updated Pokémon Transfer guide [Reddit]