"Geez, I can't believe on my first day as a vampire, I sucked off a hobo!"
"That's not the first time I've shot off in a guy's face."
"Ooo, I love a good manhole!"
The Youtube user account is named ObeyMyRod and the channel name is "Marik Plays With Himself."
There's one point in the game where Jeanette flirtatiously tells Marik's character to come back to her soon because she can only "amuse" herself for so long. Marik, who almost certainly has no clue what she's actually referring to, promptly tells her that she probably wasn't doing it enough. And then remarks that "amusing himself" was basically all there was to do back when he lived in a tomb.
Awesome, but Impractical: Porn magazines stapled together with gold that you can't even read without lessening the value. "It's kind of ineffectual as porn itself, but... it's a good collector's item."
Big Fancy House: "Oh, hey, it's one of Mel Gibson's more modest properties."
Big "NO!": "I'll just work on my tan. Wait.... I'm a vampire.... I... no longer... have... a... tan... NOOO!!"
Bouquet Toss: "If anybody else lays a finger on those flowers, I will murder them!"
Bread, Eggs, Breaded Eggs: "This game has taught me that if you live in Hollywood, you're either a Serial Killer or a vampire. Or a vampire serial killer. Or a serial killer who specializes in killing vampires. Those are the options, pick one."
He hears a girl in another room making sobbing screams, but assumes those are sex sounds, and coming from the washing machines in the room he's in.
Slender Man does this to himself in part 9
Melvin: Hey, Slender Man, remember that time you disguised yourself as one of those store window mannequins, and when people walked by, you'd wrap your tentacles around them and just devour them whole?
Slender Man: ThAt WaS aN aMuSiNg PrAnK. ThEy WeRe NoT aBlE tO pUrChAsE tHeIr ClOtHeS. ThEiR dAy WaS rUiNeD.
Melvin: Yes, and you also killed them.
Slender Man: ThAt AlSo WaS fUnNy.
"Okay, orgasm ... didn't expect that ..." - about Heather.
Double Entendre: Bakura slips in a few pretty great ones while hitting on Marik.
Marik: You know, most people already know that when you open a dictionary and you look up the word "sexy" that it has a picture of me. More specifically a picture of my bottom. Because that is where I store my sexiness.
Bakura: Marik, can I borrow your dictionary?
Marik: Why do you need a dictionary?
Bakura: Uh, I'm doing a crossword puzzle. A very hard crossword puzzle.
Easily Forgiven: When first visiting the Asylum, Marik is utterly disgusted by the big, bald, insensitive jerk of a bartender who dared to make light of Artax's death. The next time he visits the Asylum, Marik wants to team up with him as a fellow tattooed person.
Even Evil Has Standards: Melvin draws the line at pretending to be a Jehovah's Witness. "Come on, Slender Man, we're not that evil!" (Then they both burst out laughing.)
Foreshadowing: Several times in the first five episodes Marik makes comments about how "It can't get any worse" or "I'm sure there's nothing that bad waiting on the other side of this manhole." Anyone who's played the game can guess this is leading up to the infamous Oceanside Hotel level.
Episode 5 has Marik spotting a statue and asks Bakura if it looks like "that guy who tried to star in [their] movie". Next episode, Slendy drops by and offers to help play the game.
In the very beginning of episode 8, Marik says he feels the sudden urge of kill his family. In the last minutes of the episode, Melvin takes over him and stays, and even gets to play all of episode 9.
He then steers it right into Medium Awareness territory by following that up with a dialogue option that describes his life as a made-for-TV movie.
If you look carefully, immediately after "Rock Me Amadeus" starts playing, you can see Therese looking around the room with an expression that pretty much says "Where the hell is this music coming from?" while avoiding eye-contact.
Get a Room!: "Ah, the washing machines are having sex! You guys are gross, get a frigging laundry room."
"THAT DOES IT! No more Mr. Nice Marik... Not that there ever was a Mr. Nice Marik because I am an evil villain! But if there were a Nice Marik, then he wouldn't exist because I JUST KILLED HIM!Because I'm evil."
Jump Scare: Not quite in the game, just Marik was easily startled.
"Ahh! Don't do that!"
Kick the Dog: Marik was in really high spirits and good mood after a good time of singing a song parody of "Rock Me Amadeus" until...
Murder-Suicide: "Wait, how does that work? What do you do, you kill somebody who's trying to commit suicide? Do you try and hang yourself and when you drop, you land on somebody and it breaks their neck or something?"
Ninja Pirate Zombie Robot: "What am I, part of a friggin' vampire terrorist cell?" *beat* "Oh my God, I hope I'm part of a friggin' vampire terrorist cell!"
"Look at this room! Seriously, it's like something you build in The Sims when you have no idea what you're doing. I mean, not that I would know, because I only play manly games like... Call of Gears of Duty Madden 2012."
Marik, Sucking the blood out of the neck of a prostitute: Aww... You know it's true love when your partner decides to drink blood from your neck. Ahh... the sweet tastes of cigarettes and regret... Wait, What happened? She's not moving... Why isn't she moving..? Prostitute lady!?
In episode 9, Slender Man responds to the use of the phrase "This guy takes the cake," with "And probably ate it too!" Melvin tells him, "Shut up, Slender Man. You're not funny." in a reference to the Bonds Beyond Time Abridged movie, where LittleKuriboh made the same joke with ShadyVox.
Marik talks about how he and Bakura met and compares them to several friend duos, including Finn and Jake. Bakura goes on to suggest Kurogane and Fai, which Marik says doesn't apply because those two "touch butts with each other."
Strange Minds Think Alike: In episode 6, Bakura suggests that Marik appease Mel Gibson by giving him a blowjob. Later in the episode, Slender Man shows up. When Marik asks what Slender Man thinks he should do to get rid of Mel Gibson, he asks if Marik tried giving him a blowjob.
There Is Only One Bed: Marik mentions this happened to him and Bakura once. Bakura still dreams about it - uh, has nightmares about it.
This is also a Mythology Gag to LittleKuriboh's Thiefshipping fanfiction Marik and Bakura go to Censored Town, where this does indeed happen.
Took a Level in Badass: After spending the past 5 episodes being constantly thwarted by the sinister doors, Marik acquires amazing door opening skills, that even allow him to open doors with his mind without him even knowing about it.
Marik: Oh, by the way, I've heard some rumors flying around that Bakura and I... well, you know, so I'd like to address those rumors right now, I'd like to "come out of the closet", you might say. Bakura: Marik... Marik: It's okay, Bakura, I know what I'm doing. It's true: Bakura and I...are evil! And we're not ashamed of it!
It happens again in 7.5. Marik apparently decides to address those rumors once and for all.
"Y'see, technically KILL YOUR FAMILY KILL YOUR FAMILY KILL YOUR FAMILY"
Vampire Bites Suck: "Even if you suck, you're doing a good job and it gives you experience for it."
Verbal Tic: "You know, sometimes I wonder if I say the word 'frig' too much. Then I realize, who the frig even cares? Frig it."