Creating your own enemy
So, I was playing TFT and I was thinking about selling garen so I did. But I was holding him and sold him with the e hotkey, at the same time, I placed him onto my bench. His health bar became red like an enemy's and I wasn't able to sell him or get rid of him. I also tried placing him on the board, but he didn't count as my champ when the battle started so the game put in the leftmost champ. BUT. Garen was still on the board with his red hp bar. And...STARTED FIGHTING ME LOL. But 1* Garen is pretty weak so that wasn't too bad. I also tried to see if promoting him would remove that status, nope. I also noticed that the Garen would also fight the enemy team if he was closer to them than he was to my characters.
It just caused all sorts of weird effects with him, and in a ranked game nonetheless! Which I won. Because 3* Kennen and Veigar.
Edit: Looked through the boards a bit, seems like I'm definitely not the only one. But this bug is pretty game breaking at any rate.
Edit 2: The result of using this bug for shit n giggles. If the "sold" army wins, they still attack you. They're sorta like if the PvE monsters were on the board.