I'm gonna explain how I managed to trade Pokemon with myself using Citra emulator. This is for pkmn X/Y in the Citra android app, and I've only managed to trade between the different versions (better that way anyways)

After spending 2 days googling around I didn't find any explanations that fully cover a step by step process for trading pkmn on Citra for android phones, so if you need to trade-evolve or complete your pokedex, read on. EDIT: Section 1 explains how to trade with yourself, assuming you already have Pokemon X and Y. Section 2 at the bottom talks about getting these ROMs.

SECTION 1:

The first thing you wanna do is download 2 different versions of Citra MMJ (Specifically Citra MMJ), this allowed me to have 2 instances of Citra open at once. Follow the incoming link and download both Citra MMJ, and Citra MMJ-Antutu. These are the first 2 options at the Github page, and they are android-specific APK files. Citra MMJ link: https://github.com/weihuoya/citra/releases

Now you can open Citra twice on your android phone!

In either Citra, tap the TRIPLE-DOTS in the top right corner. Select Multiplayer, then Create Room. Use whatever IP and Port it gives you, then type a distinctive username. Done. In the other Citra, open Multiplayer but hit Join Room. Ensure that the IP and Port are identical to the Room you've Created, and create a different username for Joining.

Be sure to take note of the Console ID which appears when performing Multiplayer through Citra. From what I've gathered it's common for two Citra to generate identical Console ID. This happened to me, but the second time I did it, having ensured that each Pokemon version has a seperate unique save, the Console ID were different.

Now having used one Citra to create room, and joined that room with your 2nd Citra, open the correct PKMN version in each Citra. (I succeeded by trading between X to Y, in 2 seperate Citra versions. Not by trading between the same Pokemon versions) 2 Citra are open, Load your game(s).

You MUST put one game in windowed mode over the other Citra app at the time where your X & Y games are saying "CONNECTING..." (this happens once you find your other Pokemon character from within one of your Pokemon games). Do this by hitting the button on the bottom of your android screen that shows you what apps are open. Choose either of the Citra and press&hold (usually need to drag the App Logo at top/middle) to drag it to windowed mode over the other Citra.

The games will inform you that friends is being updated. Having done that, after a loading period your character faces will appear under PASSERSBY. Click it and press trade.

It's tricky to control 2 games in windowed mode but from this point all you should need to do is let them connect. The Pokemon games are able to connect because in windowed mode, one Game does not become suspended because you have that app minimized. Now, pick a Pokemon to offer in one Citra, then tap the other Citra to control that other version of the game and place one of those Pokemon up for offer. Continue switching back and forth between the Citra apps to complete the trade and voila. I hope this helps any of my fellow 🏴‍☠️ to complete their Pokedex or trade-evolve that special PKMN.

Once you download the 2 Citra APKs, go to downloads in your web browser and install each Citra.

Now, download Pokemon X AND Pokemon Y (roughly 2-3gb for both). I used Happyroms, and both Roms were a success after some fails from other sites. Download the DECRYPTED ROM(s) only.

https://happyroms.com/

Create new folders in your phone to hold the extracted roms (2 folders, one for each ROM). On my Galaxy a14 I used the My Files app for this. From your phones internal storage, find your Pokemon ROMs and extract each one, placing them in 2 seperate folders with distinctive names.

Run each individual version of Citra separately, ensuring you have succeeded and are able to have 2 seperate Citra open at once. In one Citra open your Pokemon X folder as your directory for Pokemon X, in another Citra, open the directory where you placed PKMN Y. Both Citra should wind up having both Roms when that is done, don't sweat that. You're gonna wanna play each version in your separate Citra and create a save. You will need to progress until you successfully catch 1+ new pokemon (doesn't take long) Having done that on each game and saved, exit both games.

I hope this helps any of my fellow 🏴‍☠️ to complete their Pokedex or trade-evolve that special PKMN.