Before them the earth shakes, the heavens tremble, the sun and moon are darkened, and the stars no longer shine.
-Joel 2:10, Christian Bible
When the Reapers descended on Earth, the second most common thoughts were "Shepard was right." along with "We're all going to die." and "Oh, shit." The most common thought, in different variations, and by several margins of magnitude, was "I don't believe this is happening."
Humans are predictable that way.
The good news, at least for humanity, was the world-wide instant disbelief caused paradox to suffer a DDOS attack. It normally wouldn't take long for paradox to get back on track, but sadly for the Reapers, their continued presence would continue to inhibit this until it was too late.
By the time the Reapers actually attacked Earth, all of Earth's supernatural denizens knew it was coming long ago. It's not like they were surprised an ancient force was lying in wait to destroy all its enemies; it was a perfectly legitimate attack strategy they practiced among themselves, after all. Plus, the ability to see the future also helped.
So when the Reapers burst through the Relay around Pluto, and hurled themselves at the Earth, their dramatic entrance and assault was spoiled when Earth's atmosphere hardened into a solid shield and smeared the first few Reapers that tried to dramatically dive onto the 'defenseless' planet.
Internet video of space-suited astronauts tinkering with satellites at the edge of Earth's atmosphere just before this event was seen as a hoax; the cross-legged naked old men beating on drums while floating in space next to them seemed like bad video editing, at best.
The next few Reapers that got to Earth were a bit more cautious; planetary shields were a bit outside of the normal reaping process. Unfortunately, all this caution meant they were easier targets for surface based annihilation beam weapons and other, stranger, weapons including missiles spewing metal-eating viruses, flying wooden coffins that somehow couldn't be hit, but turned anything near them into dust, and death rays coming from the sun itself.
Angered and a little embarrassed that their overwhelming attack wasn't going as planned, the Reaper forces seized the shield and in a coordinated burst of strength, crushed it between their mighty, mighty tentacles. Mollified that things were back on track, they proceeded to land on the densely populated cities of Earth, eager to convert the native population into husks to fuel their march across the sentients of the galaxy.
Things started to go wrong again immediately; the Reaper descending on Tokyo was abruptly knocked off course when it was apparently hit with a flying kick from a single human who wasn't wearing a shirt. Landing face first in Tokyo Bay, it found itself under attack from numerous sources, including sharks with laser beams attached to their heads. Each time it tried to straighten itself, it was knocked back down into the water by more figures appearing out of nowhere, who proceeded to kick it in the face before disappearing. These blows somehow were strong enough to cause it to upend into the water again and again, and the Reaper died without being able to kill a single human.
Other attacks went better, of course.
New York fell within twenty minutes, and the Reaper there began to convert the local population on schedule. However, after a few hours, night fell and the New York Reaper quickly realized that the only reason things went so easily for it earlier was it attacked during the daytime. Ferocious man-shaped monsters tore through its own army of less effective man-shaped monsters, and proceeded to display a range of abilities far beyond what it understood to be humanly capable. It got slightly concerned when several of these monsters began to bodily attack itself, even biting its body, but by the time it stopped trying to defend itself and try to escape, it was too late. Bitten and sucked dry by hundreds of vampires, it was messily diablerized. This in turn would become a problem in itself, but the Reaper wasn't around to appreciate that.
Similar stories were occurring around the globe.
After carefully herding together the docile local population in Kansas City, the Reaper was surprised when the populace popped chainguns out of their bodies and shredded it with mass effect charged hyper velocity rounds.
Several Reapers reported their forces were being ripped apart by things jumping out of mirrors, water, and other reflective surfaces; hulking ferocious beasts of unstoppable destruction who then vanished into thin air.
Others had all manner of bizarre phenomena happen to them, ranging from being repeatedly struck by lightning to going crazy and attacking other Reapers.
Even where things were not going disastrously wrong, things were still not going right. Somehow the humans still had power and communications going despite the Reapers shelling all power stations and destroying every communication satellite they found. Messages were going across the globe urging humanity to resist, and local communications were directing people to shelters, weapon caches, and coordinating defense and attacks against the Reapers.
This was becoming a problem.
More and more Reapers were being recalled to continue the assault on Earth; instead of being a galaxy-wide omni-present strike, the Reapers were becoming bogged down by a single planet.
Even as more and more Reapers poured into the solar system, the Reapers on Earth faced a hard truth; they couldn't leave. When they tried to leave Earth's atmosphere, they were shredded by countless invisible blades. They had never encountered anything like this before, in almost a billion years of harvesting.
Then the Antediluvians woke up.
AN: This story could have come in two flavors; mage only, or all the oWoD crammed together. As this is a humor piece and not designed to be taken seriously, I find it more hilarious if I throw everything into the pot. It also could have been a grim depressing desperate struggle for survival as per the World of Darkness setting. Unfortunately for the Reapers, their inclusion has made the Tellurian a less darker place.