Other Danny Phantom Crossovers
A while back, like a long while, I mentioned how difficult it is for Danny Phantom to be crossed over with other universes besides DC Comics without having to massively downplay Danny due to his powerset and shown stats, or by putting him in of a non-combat oriented setting, thus negating his primary genre and the fact that he has powers. And I stand by that. However, recently I was encouraged to first explain why I think Danny can't fit into specific verses, and then try to find some ways around this issue and come up with ideas for how Danny Phantom can be in a crossover WITHOUT him breaking the tension of the other verse and without him being nerfed to Hell and back. So, after a bit of thought, here are some ideas for IPs other than DC Comics that I believe Danny Phantom can be crossed over with and how it can be done without breaking the story of the other verse or crippling Danny's showcased abilities.
Starting with an easy one here that is honestly just cheating since DC and Marvel have so many overlapping building blocks. The same reasons Danny can function in DC without breaking things are why he can work in Marvel. There are people with comparable or vastly superior stats, people who can counter his hax with gear or magic, and the way his powers work don't massively outmatch how the powers of Marvel work. Easy.
This one is slightly more difficult, but not by much. There are ways for various characters to get the tech or magical items needed to counter Danny's hax, and Danny's showcased, canonical stats are outclassed by the high-tier combatants, but once you get passed that, the issues start cropping up. Danny has durability negation and high-level mind control, two abilities that mean he can act as a hard counter to the biggest threats in the verse, the Viltrumites. They can't hurt him, he can kill them easily. It basically negates all the main tension from the primary threat. And even if you go to the secondary threats, like the Sequids, Danny still acts as a hard counter, since the threat from the Sequids originally came from their pure numbers, which Danny can overcome with ranged and AOE attacks, types of attack that no one outside of Rex-Plode and Atom-Eve has really shown (and Tek-Jacket, but they usually don't show up for fights for various reasons). This means Danny not only negates the threat of the Viltrumites-- none of whom would carry anti-ghost tech or use magic due to lacking knowledge of ghosts and their own pride-- and covers a type of combat that would have saved the heroes of the verse a LOT of pain if they had access to it.
So how does Danny work in Invincible without breaking the verse or nerfing him? Take advantage of the Ghost Zone being a separate dimension with its own threats that also come to Earth. Where was Danny when Omni-Man was wrecking Mark? He was stopping Aragon from overthrowing his sister to reclaim his crown and lead an army of ghostly knights against Earth in revenge for the humiliation Danny caused him. When Conquest showed up? He's freezing Undergrowth's vines before the plant ghost can take over Amity Park again. Whenever a big, very important fight happens, make it so Danny isn't there to be part of it. Have him show up for lesser fights, like the Flaxan invasions or the Sequid incidents and have him be a major part in containing the threat, maybe even have the Flaxans be the first to develop anti-ghost weapons outside of the Fentons and the GDA confiscates what they can to make their own, thus giving Danny a reason to distrust them like he does the GIW.
Danny would make any Invincible fights he took part in WAY easier for the heroes, so keep him out of the ones that NEED to happen and be close calls, and have him be a true asset in the ones he does take part in.
This one is harder. Yes Danny's stats are below the highest end characters, but he is above the vast majority in raw power, has far more abilities than anyone besides All For One, and the powers he does have work in ways that are just outright better than the versions we see in MHA. Most notably, one of the most impressive and combat capable Quirks we see is Permiation, which is so powerful and effective that the only way to defeat Mirio is to attack non-combatants and force Mirio to take the hits to save them. This wouldn't work with Danny because he can make those he touches intangible as well, so the trick Overhaul did with Eri wouldn't do shit. Not only that, but while Mirio's Permiation can work as the Ultimate Defense, it lacks Duability Negation due to how it's safety feature works, but Danny's intangibility doesn't have that issue, meaning he can bypass conventional durability and either mind control or kill people with ease. The only one who would be safe is All For One, who has some form of regeneration that MIGHT save him if Danny phased his heart out, and his messed-up mindscape with the hundreds of 'echos' that may make Danny's Overshadowing ineffective
So how does Danny work in this verse? Make Danny's time in this verse a job given to him by Clockwork. Danny can't solve the issues of this world, only ensure certain characters reach their peaks so THEY can fix the problems. No shooting Shigaraki at the USJ with a Ghost Ray to knock him out and arrest him, no sneaking into Overhaul's base and sneaking Eri out after destroying the Quirk Destroying Drug, and no showing up at All Might's Last Stand fight and sending a nuclear-level blast into All For One's face to remove his head. Instead, Danny is there to help train Deku in how to use the energy of One For All, to go to school to get proper combat training and emergency response skills, and spend time in a place where he isn't a freak. As for his powers, have Danny present himself as two people. There's 'Danny', a hero student who can project and manipulate energy, allowing him to have superstrength, flight, energy blasts, et cetra, and then there is 'Phantom', a vigilante or random criminal who can turn invisible and intangible. He has all his powers, he just doesn't use them all at once, instead giving each ID a powerset that lets them perform different functions.
4. Hazbin Hotel/Helluva Boss
Just have Danny's hax of durability and attack negation be negated by high level magic attacks. Adam, the Sins, Charlie, maybe Vox and Alistor, they can all hit him even when he goes intangible. Their magic system is fast paced and powerful enough to match or outmatch what Danny can throw around in canon, many characters can fly, and at least a few people have the raw stats that Danny can't just blitz them or one shot them with a single punch. Honestly, the downside to this crossover comes from how they are mostly political or relationship dramas and not combat-oriented, so unless you make Danny pretty OOC and break up some canon pairings, there isn't much for Danny to do outside of a few big events.
This one is interesting. Danny's raw stats in canon are probably A-Class level, with fanon stats being high S-Class, and unlike with Invincible, his Durability Negation isn't a hard counter against the big bads, since a lot of them have some form of regeneration. Honestly, outside the fact that other than maybe Psychers, no one can actually hurt Danny through his intangibility and his own rapid regeneration, Danny would fit in this story VERY well. He doesn't even have any powers other than his intangability that would make him instantly better than the rest of the cast. Genos can fire energy blasts just as fast and probably with far more powerful than Danny can, Flashy Flash is far faster than Danny's canonical speed, Tank Top Master is probably just as strong as Danny's canonical physical strength, et cetra. So... I guess I have more to say on this one... Huh.