Nicola Adel basically marches to his own tune. After Urias challenges him, he gets goaded to begin to unleash his true power... but then stops and leaves, because he's too hungry to continue.
As Nicola Adel shows Luna around Isunia, a challenger shows up, trying to best him so that he can become a one-man guild too. Nicola, without missing a beat, punches the challenger so hard that he flies off into the distance. Nicola later reveals that this happens on a regular basis.
As Nicola advises Luna to eat more so that she can grow taller, he promptly shoves a full sandwich to the girl's mouth, which led to him receiving a sermon from Marlone:
Marlone: You can't just put things into other peoples' mouths!
Mono is quite knowledgeable for a robot when it comes to sarcasm, as her interactions with Urias can attest.
In Naterra, Ladica is fluent in "the dialect of the ancients." Said dialect just so happens to feature a lot of chatspeak, to the point where "Lol" said as a single word could be considered Ladica's catchphrase.
Really, the fact that Naterra's previous civilization was apparently full of Leet Lingo-speaking Valley Girls.
At the start of Lainecrest: Testament, Amaryllis first comes in with an abandoned magical doll. Lyelth eventually offers to fix the doll, in exchange for a book recommendation from her. The next day, Amaryllis comes in bringing a malformed magical being. Lyelth puts his foot down and refuses to look after it.
Cards — Voice Acting
Despite the general dramatic attitude for most of the game, some of the cards utter incredibly ridiculous lines and that cause some laughs and chuckles:
Summon a Snowman, and you hear "Golly, it's chilly here!" In the past, if you summon multiple Snowmen at once, and it overlaps with itself, resulting in "Golly, it's— Golly, it's— Golly, it's— Golly, it's chilly here!"note Now, the line only plays once as all the tokens are brought in at the same time rather than in sequence. It gets even funnier if the swarm of Snowmen end up being the cause of the opponent's demise.
Grimnir's Badass Boast when played is also a gem, especially in Japanese. If you manage to use him at Turn 10 (which activates his Enhance effect), his Badass Boast is so long that he talks through the entirety of his effect's animation.note Yes, this includes his previous, slower animation.
Flame Rat is funny in general, but his line at the start of the player's turn who has him takes the cake: "Eeek! I'm on fire!" Even funnier when this causes the opponent to take lethal damage.
Floral Fencer has an incredibly silly line whenever she attacks, "Stop staring!" The way she says this line implies that the player happens to be a pervert and looking up her skirt.
Timeless Witch's boredom with eternity seeps into her voice acting. She yawns while attacking, and only gives a sigh and a resigned "Whatever" when she dies.
Orthrus is perfectly capable of talking normally, but she barks when she attacks and actually whimpers like an injured dog when killed.
Marian the Mummy communicates in muffled sounds, since she's completely wrapped in bandages. If you evolve her, the bandages come off, and she speaks like a Valley Girl.
"Mmmh... Omigod! Finally!"
Upon being destroyed, most cards either say something along the lines of This Cannot Be! or simply groan. Some, however, have some pretty amusing reactions upon death.
There exists a mod for the game called the "Summertime mod" which changes the card arts of various cards into summer themed version of their arts. While mostly having female and a handful of male in characters swimsuits as probably is expected, it also has some rather funny inclusions such as Jeno, Blood Wolf, Tart Man and the common Skeleton.
"C'mon, Goblin Mage! We've got treasure to hunt!" "Ooh! Feena, I found some shiny stuff!" "Wait, don't touch that! It's a tr—" —Feena and Goblin Mage, falling for an obvious trap.
The evolved text shows that things aren't exactly getting better.
"F-failure? Ha! I don't know the meaning of the word!" "Ah! There's something shiny on the floor! Yoink!" "Did you hear a click just now?" —Feena and Goblin Mage, about to fall into an oubliette.
"I'll put in my hours, but don't expect me to clock in any overtime. What... I dropped something, you say? O-oh, that's the HaZeus fanfic I wrote! Y-you're a fan too? Omigosh, let's gush! HaZeus or Zeudes? I just can't choose my OTP!"
Elegance in Action, the title of the card mixed with the art of a maid stumbling around is just snark at its best. The description just seals the deal.
"Visitors to the mansion always depart with an item gifted in apology."
Leaders
While most of the funny lines come from the cards, the alternate Shadowcraft leader Mordecai manages get a little gem with his sorry emote. It's something especially amusing hearing a skeletal knight saying sorry in such a silly and childish tone.
A lot of leaders usually have subtle facial expressions in their victory or defeat screens, but one noticeable facial expression that considered hilarious is Cagilostro's evil grin◊ in the Victory screen, which has become a meme within the fandom of how over the top the facial expression is.
Miyako, if defeated, screams that she's dying... and then realizes that, as a poltergeist, she's already dead.
Galmieux is one of the haughtiest leader skins, and her voice lines show.
Your opponent establishing lethal for their next turn and emoting over it? Rude. The same opponent getting eliminated by a card they didn't expect? Gratifying.
There is an inherent humor with several Forced Transformation effects, largely due to what the cards get transformed into. Transforming the mighty Bahamut into a much less harmful Snowman or a Flame Rat is a lot more humiliating than destroying or banishing it.
There has been a recorded case where someone won a game by milling the opponent's cards straight to zero.
Much more common but less dramatic are cases where a player has replaced their deck with Prince of Cocytus but left a Vile Violet Dragon on the board. A crafty opponent can deal chip damage to Vile Violet enough times to force the opponent to draw out their small deck. Winning a game this way is often an Awesome Moment for the player.
The Gold Pina Colata in the Idolmaster Cinderella Girls is infuriating to fight when it gets random amulets and strong Tokens in turns far earlier than it should. But sometimes it screws up royally and gets board-locked with a field full of amulets that it can't get rid of by itself. It's a cathartic situation, especially if you've been struggling against it.
Alice gets a retrain in the Azvaldt mini-expansion! But when you take her previous appearance in context — namely that she was the face of Wonderland Dreams and the focus of a lot of its problems, it can be interpreted that she was imprisoned in Azvaldt for causing all those issues in her heyday.
Anime
Episode 14 is one of the sillier ones — Hiiro squares off with the eccentric Marcel, and he's left baffled by the chef's behavior. Even Marcel's entire deck is ridiculous, as a mostly neutral deck with a cooking theme using sillier cards like Hamsa, Ultimate Carrot, and Humpty Dumpty.
In episode 26, Alice eyes a prize in a crane game and Kai scoffs at it, calling it immature. Alice taunts him, saying that even a "genius among geniuses" has his limits. Without missing a beat, Kai starts formulating a strategy to claim the prize.