Accidental Innuendo: Taokaka's name might be strange to hear for some Spanish and Western fans, since the latter half of her name sounds like "caca", which is slang for excrement. This also means that the Kaka Clan as a whole can sound more like "Poop Clan".
Difficulty Spike: Your punishment for blowing through the first nine Arcade Mode stages with Nu -No.13- is having Unlimited Rachel as the final stage. Have fun!
Draco in Leather Pants: Jin gets along well with people, even Noel; he just doesn't say anything about his confusion. His jerkassness/partial insanity is a result of the Ikaruga War combined with him finding out that the brother he killed is still alive and remembering his past. This paid off. He's now one of the genuine good guys.
Jin's Ice Car spam. So much that it was nerfed in Continuum Shift, because now all Jin does is spam his ice swords until he gets a health advantage and then run away waiting for the time to run out.
Carl's Calamity Trigger's semi-infinite Clap Loop caused a lot of players to dislike fighting him.
Nu-13. When played in melee (as in the 2009 Arcade Infinity finals) she's balanced (somewhat — the reach and priority on her C-attacks is far better than they should be). However an expert Nu player will use her knockback and teleport moves to avoid melee at all costs. Staying at range lets her play defensively, and abuse her absurd projectile combos. While BlazBlue's system does penalize excessive defensive play, Nu is allowed to stay defensive longer than any other character before being penalized. Longer even than Hakumen, who's meant to play a defensive/counterattack game.
Ragna seems to be prone to this, like his younger brother/Rival, Jin. He has also been paired with almost every character from the series. What even adds to this is Rachel's Funny Ending. And just like Jin, this is not limited within the series. There're fanarts and fanfictions of Ragna being paired with Rita Mordio, Kohaku, Heart Aino, Lambdadelta, Souseiseki, Sol Badguy, Flandre Scarlet, Rumia, and more. And then, there's the official April Fool's BlazBlue X Arcana Heart - Crossover Flash Game hosted by the companies of both franchises. Where Ragna is on a date with Heart. Oooooohhh, boy...
People have paired Carl with Makoto, Noel, Litchi, Rachel, Taokaka, Platinum, Linhua, and especially Ada. And most, if not all of these manage to make sense within canon. And, of course, this isn't limited to characters within the series, as he has been shipped with Rita Mordio(mainly due to both characters being voiced by Michelle Ruff), AliceMargatroid, DorothyAlbright, May, ABA, and Bridget, among others.
Iron Tager started off a general trend of ArcSys games having very unbalanced grapplers (and not in a good way). He's huge, slow, has bad normals, struggles against airborne opponents, can't combo to save his life, needs his magnetism to get any work done while also struggling to apply it to the opponent, and his few high-damage options, like his theoretically good command grabs, lead to the opponent being on the far side of the screen, which is the opposite of what a Close-Range Combatant wants. The Dustloop wiki's article on Tager lists his sole positive as the fact that he can, theoretically, still win games.
Hakumen is quite strong in theory. He has a number of strong normals and specials that deal a lot of damage and have quite a bit of utility on top of that. However, all of it comes with catches — he has a grand total of ONE gatling route, which limits his combos significantly. He does have the unique ability to cancel specials into other specials, but the unique way his Heat gauge works means that all of them cost meter that he struggles to get. Not helping matters is his generally poor mobility, since his dashes are incredibly slow, and he has the proud honor of being the only character whose backdash completely lacks invincibility frames. He can make people explode if he does have meter, but not only is that a particularly massive "if", there are plenty of other characters who can do that with significantly less effort involved.
Some fans hate Carl because he's very weak. These people tend to not use his drive ability properly, which requires Carl and Ada to attack in tandem. This is very visible with his Astral Finish, as the enemy can easily avoid it unless Carl does some serious work. On the other side of the spectrum, some hate him because of the Clap Loop. Never mind the fact that it's extremely difficult to get the timing and inputs right, or even to set up, since most people with half a brain will want to stay the hell away from Nirvana.
Memetic Mutation: Carl is known by many people as a pimp, mostly having to do with his almost all-purple wardrobe, complete with a pimp hat.
Narm: Before the start of Carl's fight with Nu-13 he says "I'll do my best, sis. I want to taste your cooking again." in the most dead-serious tone possible.
Porting Disaster: The PC release is apparently a bit buggy, and it uses Games For Windows Live for its online play.
The Steam release doesn't even have online play. And if you have people who can play with you locally? Getting local multiplayer to work requires setting up additional controllers in a separate launcher program, which isn't included with this version. So you have a fighting game with no multiplayer whatsoever.
It also has a glitch which cause music not to play during the Story Mode or the Arcade ending.
Arakune's Zero Vector spawns a gas cloud that either follows the opponent, tracks them from above, or tracks Arakune himself. Regardless of which type is spawned, it will curse the opponent if they touch it, allowing Arakune to run his gameplan. While it doesn't deal damage directly, the cloud still has a hitbox and deals hitstun, potentially allowing Arakune to score a combo as well.
Carl's up + D normal has Nirvana clap its hands above it, releasing a shockwave. The move is air-unblockable, which isn't unheard of, but unlike other normals with this property, it can't be Barrier blocked either. This makes it an incredibly strong anti-air, and it can be used alongside Carl's air throw to create a nigh-inescapable vortex of death.
Theme Pairing: Carl is paired with Dorothy Albright from Arcana Heart because both are short-haired blondes and Stage Magicians. Furthermore, their costumes look like color palette-swapped versions of each other.
. Also, see Launcher of a Thousand Ships below.