milliekou:

I’m not sure but I think Marik is just a variant of the Arabic name, Malik (

ملك) 

. It’s just the Japanese don’t have an L in their language system so their L turns into an R so the audience/readers get quite confused in that aspect. Although I got informed by an Arab friend that there are variants of the name Malik which include Marik so either name is cool. I use the name, Marik for the light one and Mariku for his dark half, though. ( I use Mariku, no matter how weaboo-ish it sounds because there’s this certain personality whenever I think of that name. )

What’s interesting is that Yami Marik doesn’t have an (official) name. 

That’s the reason why a lot of people have all sorts of (nick)names for him and you’re free to name him (and train)  like some sort of pokemon, lol. You can name him whatever you want, Mariku, Malik, Marik, Tategami, Kek, John Cena, etc…whatever comes to your mind.

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAUUUUUUUUUUUUUUUUUUUUUUUUUUUHHHHHHHHHHH!!!!!!!!! *tackles and adopts in a nanosecond*

Seriously though, allow Terra to explain a few things.

The thing is Marik IS Malik in every sense of the word. Marik is everything Malik ever wanted to be, could be, and hoped to become. (Not necessarily a murderer but free, confident, strong, and so very much alive and allowed to do anything he wanted with no limitations.)
But since he still had lingering feelings for his father he could not kill him but his hatred was too strong. That with the lifestyle he had growing up that he came to loath combined with the dark ritual carved into his back, this allowed an outlet that allowed Marik to be. You see, they are still the same person and that is why even the other characters in the show are always saying “Malik’s dark half” and not any other name. 

As for the fans though, well we were sick of saying “Malik’s dark half” when writing fanfiction or roleplaying that we decided since Malik was a real name as well as the name given to him in Japanese that it would belong to the one who was there first and seen as the good side.
Marik was the dub name and we all liked it because it was nice and easy to say but it still looked very similar to Malik in written works so half of us adopted adding a u to the end and took to calling him Mariku since it was easier to spot and tell the difference. 

The newer fans to this great fandom though seem to find that silly or have no idea of our ancient ways so they took to calling him other names and calling Malik by the name Marik because that is the way of the Abridged series for when it came out years later. 

I hope this was informative.