We’ve seen two recent announcements of surprising guest characters appearing in popular fighting games, and the fans have been ... vocal.

The Teenage Mutant Ninja Turtles are slated to show up in the grim DC superhero fighter Injustice 2, and the developers of Tekken 7 revealed that their next guest character — following Akuma from Street Fighter and Geese Howard from Fatal Fury — will be Final Fantasy 15 protagonist Noctis.

These kinds of surprises get people talking. Characters from other fictional worlds turn heads and bring new excitement, along with new audiences, to existing games. The dramatic character reveal is a big part of how fighting games are marketed, and guest characters are becoming the rule rather than the exception. Some players are beginning to expect visitors from other universes rather than be surprised by them.

The Smash Bros. franchise has pioneered the practice over the years, using surprise guests like Solid Snake and Cloud Strife in calculated reveals to stoke an already ravenous audience to even greater heights of anticipation. Why shouldn’t smaller games borrow a little bit of that fire?

But Smash Bros. is an anything-goes franchise whose backstory is “a hand is playing with some action figures.” While it’s expected that most games come from Nintendo-owned franchises, that’s clearly not always the case. The game’s own logic allows for anyone to show up. That goofy sense of fun is part of the appeal.

Tekken and Injustice, however, take place in more defined worlds with more specific aesthetics. This is where the anger from some fans is coming from. Is there a tonal shift when the bright multicolored headbands of the Ninja Turtles appear out of the pitch black of this dark alley? Do the dudes break the mood?

It’s helpful to remember that fighting games have never been overtly story driven, at least not in a way that’s supposed to make a lot of sense. It’s hard to write a “realistic” story that’s designed to give everyone an excuse to beat each other up in stylized environments.

That’s why the misplaced rage is so baffling; the average fighting game universe has seen a lot weirder than pizza-loving mutant turtles, and neither Injustice nor Tekken are exceptions.

Are turtles too much?

Injustice, being a relative of the Mortal Kombat series but starring Batman and other DC characters, is certainly pretty grim. The heroes are stone-faced and merciless, and the world itself is so dark that the game has literal visibility problems. But it’s also ridiculous.

The pivotal event of the Injustice story is a bad guy drugging a good guy to see his pregnant fiancee as a villain so that the hero will punch her into space, thus setting off the nuclear detonator the bad guy had implanted into her heart, which destroys a city back on earth. This is literally the story. A pregnant woman is punched into space in order to ignite a nuclear weapon.

This event, which we might gently call “wacky”, is the most important historical event in these characters’ lives: They bring it up with only the utmost gravity, in solemn terms.

Injustice may be gritty, but it is not down to earth. This is the DC universe, with superhuman powers, impractically elaborate villainous schemes and threats from beyond the stars. A visit from sewer-dwelling mutant turtles who are trained in the ninja arts and like pizza? That’s hardly the weirdest thing Batman has ever seen. There was even a comic book where they met, and it was shockingly not terrible.

The original Ninja Turtles comics were born as a dark parody anyway; the rough edges were sanded down once it became a cartoon designed to sell toys. The characters were born dark, and it’s possible that their portrayal in Injustice 2 will run closer to the moodier and violent comic version than what we’re used to from the cartoons.

Did you notice who showed up first in the trailer? It was Raphael, the edgy one. In the first film he isolated himself due to his rage and was beaten almost to death by the Foot clan. It’s not that much of a stretch.

Plus, Injustice 2 already has a flying psychic gorilla ... who is stabbed to death by Aquaman in the course of the game. There is nothing that Injustice can throw at you that’s weirder than what it has already shown; the connective tissue is more the fact the game takes all this ridiculousness completely seriously.

Tekken has always been larger than life

On paper, the Tekken series is about a family of treacherous warlords who take turns trying to kill each other in their bids for absolute power. You could be fooled into thinking it’s a serious crime drama. But Tekken is also, and forever proudly will be, the fighting game with the bear in it.

The Tekken series has featured a bear, a panda, a kangaroo, two different dinosaurs, all manner of robots and androids, a man with a leopard head, a narcoleptic vampire, Lucky Chloe and the largest number of impossible male hairdos in any fighting game by volume. These characters can go bowling together as machine-gun toting grunts watch and cheer in Tekken 7.

If you’re worried about Tekken breaking its tone, you haven’t been paying a lot of attention to it for the last twenty years. Tekken breaks tone constantly. It revels in doing so.

The “ending” cinematics from the series, all of which you can watch in Tekken 7, frequently take the characters to Looney Tunes extremes. I’m particularly fond of this excellent piece, which involves explosive golf balls and men tied to rockets.

Why would you draw the line at Noctis, a fantasy RPG hero? Does the sharp-dressed protagonist of Final Fantasy 15, slinging his magical blades from thin air, really fit into Tekken? Of course he does. If anything, over the years the fashionable men of Tekken have started to dress more and more like modern-day Final Fantasy characters. Claudio, Hwoarang, Miguel, Eddy and quite a few others could appear in a Final Fantasy game without anyone batting an eye.

As for the supernatural elements, Tekken is way in there already. It isn’t just Akuma and Geese, the guests from 2D fighting games, who are throwing around fireballs. Tekken already has eye lasers, rocket punches, flying tigers and the Devil. As in Satan.

Hands down the craziest Tekken match I have ever watched. Qudans played out of his mind. #TWTFinals pic.twitter.com/d4gJ3SosVb — NB|NGN NoGoodCitizen (@NoGoodCitizen) November 13, 2017

The finals of the Tekken World Tour were between a robot and a flying devil-man. If you’re thinking of the series exclusively as a sober battle between hardened martial artists ... you might be thinking of Bushido Blade.

Guest characters are good for the genre

Putting the fit aside, guest characters — especially the big surprises — are good for fighting games.

This is a niche genre with passionate core fans. But there are only so many of us, and to cater exclusively to a small audience will only bring about a slow death for the genre. Major fighting game developers like Tekken Project and NetherRealm have to reach outside of the niche, get fresh eyes on the genre, and make new players and fans. Gimmicky, if fun, characters are an efficient way to do that.

The Ninja Turtles comics were born as a dark parody anyway

“Just making a great game” isn’t enough, and it never has been. It made sense for Tekken 7 to embrace guest characters, because Tekken itself doesn’t have memorable characters on the level of a Ryu or Chun-Li.

The announcement of Akuma in Tekken 7 a few years back forced Street Fighter fans to stand up and take notice. Noctis’ appearance is just an extension of that experiment. It’s getting people talking, and so far it hasn’t broken the game. That’s a win.

Characters sell fighting games. Without Mario and friends in the starring roles, Smash Bros. might have never become much more than a quirky footnote in genre history. Dragon Ball FighterZ is building up Spirit Bomb-level hype with its jaw-dropping anime-style graphics, but the developer (Arc System Works) has been blowing minds in that style since Guilty Gear Xrd came out in 2014. It took Goku for the masses to care.

Surprise guest characters, the bigger the better, are simply good business. Thankfully they’re the kind of good business which happens to be good for the players as well. I’ve said it before and I’ll say it again: There is nothing wrong with more fighting game players.

So keeping all that in mind, here’s what really needs to happen: Arc System Works should add Son Goku to Guilty Gear Xrd and add Guilty Gear hero Sol Badguy to Dragon Ball FighterZ.

Call me up, guys. You can make it work.