_____________________________

These are those things that are determined by canon.
There is enough disparity between the original and the dubbed versions of the series that I feel it's appropriate to list them. I do not go by dub story for the most part, particularly in regards to characterization. I actually don't know the dub very well, for that matter (my main exposure to the series is through the manga, Toei series, and through subs).

- He was known as "My Other Self" (by Yuugi) and "The Other Yuugi" (by Anzu and crew), referred to as the "Nameless Pharaoh" by others, and finally "Atem" once he rediscovered his name.
- He has broken people's brains to protect Yuugi and his friends.
- He has cheated.
- He has given zero wits about other people. That changed.
- He has lost his temper and been a complete jerk.
- He has spoken in a very loose and informal way. He still does. So much for being regal pharaoh.
- Yuugi was his vessel, not another part of his soul. The Puzzle accepted Yuugi because his was a heart big enough to hold Atem.

Things that are Not A Thing:
- Never known as "Yami". The name "Yami" was strictly something decided by the fandom, which 4Kids either took as accurate or decided to adopt it for sake of ease in giving the nameless amnesiac a name.
- What is proper speaking? Other Yuugi/Atem has never spoken in any means that wasn't superior and informal.
-