@Estrelarius - The Harry Potter wiki page on Apparition disagrees:
"Range: Apparition had a range-limit,[5] and became increasingly difficult with the distance to be travelled. It was advised that inter-continental Apparition should only be attempted by the most highly skilled of wizards[6], otherwise risking splinching[7], severe injury, and death. Apparition also required a familiarity with the terrain of the place the wizard wanted to visit, as they needed to be able to visualise it clearly.
When Harry, Ron and Hermione were trapped by Death Eaters in Malfoy Manor, Lucius Malfoy alerted Voldemort, who was investigating Nurmengard in the Austrian Alps. In order to get to Malfoy Manor, Voldemort had to fly most of the way. He had to fly over a "stormy sea" to get within range of the manor.[3] As such, even an extremely powerful wizard like Voldemort couldn't Apparate much further than the length of England. As such, wizards apparently could not Apparate somewhere outside of range by imagining that location and Apparating small stretches at a time, as doing so would possibly cause splinching."
"Destination: Besides the user focusing in their mind on a desired place, the limitation of the choice of destination is unclear. It is most likely that the wizard or witch could only Apparate to somewhere they had seen or been to before.
Seeing a destination through a photograph or other image was usually not enough to let the user Apparate there: Dumbledore had seen a picture of The Cave in which he suspected Voldemort to have hidden a Horcrux seen in Tom Riddle's room at Wool's Orphanage. However, as Dumbledore said to Harry in his sixth year at Hogwarts, he had been trying to locate the cave for a very long time.[10] This suggests that a witch or wizard trying to Apparate needed to have some idea of where their desired destination was. It was not enough to only have seen it or know about it."
Source: https://harrypotter.fandom.com/wiki/Apparition#Description
Taking this into account, I've also realized another potential issue.
With the Nekross and their technology been protected against normal magic, it was enough to prevent Wizards from magically teleporting onboard as when Randal Moon tried to use magic to teleport Tom and Benny onboard the Zarantulas in Season 01, Episode 02, it didn't work and the boys ended up back at the magical stones.
Since we're putting the Wizarding World and Wizards vs. Aliens into the same universe for this scenario, I'm guessing Nekross technology on the Zarantulas would also prevent apparition from working - just like how you can't normally apparate into Hogwarts.
A way around this may be for a group of powerful witches/wizards to deliberately allow themselves to be captured (like Tom and Benny did in Season 01, Episode 02) before using Dark Magic on their captors.
@Estrelarius - Technically speaking, they wouldn't need to invent a spell. Since we're placing these two 'universes' into one and merging the 'rules' in the process, we know that the WvA universe has "Grim" Magic, which is their own equivalent of the Dark Arts from the Wizarding World universe. As such, the darker spells/curses could work on the Nekross.
Again, this then boils down to range - with Wizards in the Wizarding World universe not only having not gone out into space and been highly resistant to change. Heck, back when Ottaline Gambol suggested using a Muggle Steam Train to get all Hogwarts students to school at the same time in 1830, it resulted in a massive operation just to acquire the locomotive and carriages from Crewe in the first place. This was then followed by Pure Blooded wizards whining about it by saying that using Muggle transportation to get their kids to Hogwarts was "unsafe, insanitary, and demeaning"; the MOM having to literally threaten them by refusing to let their kids go to Hogwarts if they didn't use the train just to get the Pure Bloods to shut up.
Theoretically (and copying what I've written in another thread on the Harry Potter wiki), you could have Wizards in America pull a similar stunt; stealing one of the 'retired' space shuttles - leaving a duplicate in its place - and modifying it with magic to allow them to have a spacecraft to use.
Make it big enough on the inside to fit multiple wizards (all of whom have been cleared to use curses and other dark magic), equip he shuttle with shield charms to protect it from laser fire and get close enough to the Zarantulas for apparition and you may get a victory if you're lucky.
Makes me think a bit of this - just replace the Spitfires with a Space huttle and the Dalek saucer with the Zarantulas:
https://www.youtube.com/watch?v=olUkx6jNfCg
However, there's a lot of "what ifs?" and obstacles to overcome with that plan - not to mention that the Nekross could easily summon their fleet to blow Earth apart like what they nearly did in the finale of Season 2.
Not saying it would be impossible for the Wizards to win, but it would be very risky.
@Estrelarius - Question is, how long would it take and would it require active Nekross technology to be in the possession of Wizards before they could attempt it?
@Estrelarius - True.
On the flip side, however, Wizards from the Harry Potter universe have never gotten into space (unless you believe the story in the Quibbler about a Wizard flying to the moon on a broomstick and bringing back "moon frogs", which is likely false) and presumably don't have any magical protection against off-world threats.
Combine that with the Neckross having weapons that can wipe out entire planets, I don't think it would go well for the Wizarding World if the Neckross decided to follow Chancellor Kooth's plan of just blowing up Earth.
