The All-Fandom Realm

It is time, people. As our numbers grow, so does our opposition. While you all are here, I would like as many people as possible to share with us some threats that your characters would be likely to face in their home worlds! I shall start:

Angler here faces off against the nefarious Octarians! They are a race of, uh, severed tentacles who use evil technology to spread their own ink across the world in order to take it over!

There are also the Salmonoids, big, bloated fish... things whose eggs are very valuable, but who themselves are very aggressive and violent, and somehow also like slinging green ink around.

While many organizations, such as Cipher, Team Plasma, and Team Galactic have likely not been together in some time, there are likely stragglers out there that still carry the goals they once hold and hope to eventually realize them. Albeit, since their numbers are much smaller, its doubtful they can do much now, right?

Unless, say, one plans a resurgence, but surely that won't happen, especially in a place like this, surely.

(((Hope you don't mind me linking these, I figured it would make having any relevant information a lot easier to have)))

For Seren, the threat is pretty much just predators and vengeful creatures. The main threat of the Ori series is the decay that is caused when a spirit tree loses its strength to govern its land - usually caused by some big angry creature that for some reason attacked the tree.

When a spirit tree dies, the spirits who were born from it all eventually die out as well, so... whilst the decay is something that unlikely to spread from beyond Seren's world and thus any encounters with it would have to occur within said world... it wouldn't work out so well for the decay to come from Seren's home region, given the implications.

Seren doesn't have any personal enemies, so it's unlikely anything would come through the portal with hostile purposes from their homeland.

Not at all. Go right ahead.

Using Neo's profile so I can add some foes from the Arknights universe!

There is an extremist group called Reunion, though (spoilers for late-game) they've since dissolved after it was revealed their leader was controlled by another antagonistic force

Despite this though, there are plenty of people that are willing to kill their opponents, whether for simply needing the money or sociopolitical motivations. Being an Infected is also rather dangerous in general (beside having a terminal illness), as quite a few of Terra's nations are hostile to them in some capacity, even outright imprisoning them for their condition (It doesn't help there are politically-driven misinformation out and about). Even being non-infected, a lot of the nations' leadership are corrupted in some capacity and as a result, may be dangerous if something is done they don't like.

The shortest answer to this is Terra itself is rather hostile, and you can easily make anyone an enemy if you aren't careful.

She isn't aware of them yet, but considering the myriad of jobs her and Shadow have done (some a bit ethically questionable) so they could keep their heads above water, it wouldn't be surprising if anyone had a grudge or were perhaps looking for a reason to attack them.

Oh boy, a chance to make a bunch of named, unique NPCs that aren't at all an organization all together (But there could be organizations of them regardless):

Stand Users.

Not that all Stand Users fit the antagonist role, it's just that they're drawn to each other by fate(?) and it gives me an excuse to be overly creative.

Anyway they're called that because they have these spiritual-manifestation-thing-a-ma-bobs called Stands (Don't bother with a clear explanation why Stands are called that) and Marcus is a Stand User but he's not evil but there are many who would gladly try to take over the world.

Need the general Stand Rules? Look at Marcus's Important Info tab. Want a Stand? Ask me how you get one and I can figure something out for your character personally because I have read way too far into this franchise.

From Teyvat, a new threat expands their horizons. A fallen human society turned to wretched monsters:

The Abyss Order

Mages, mid- to high-level elemental magic and mysterious unrelated powers... and too many to count, at that.

Their goal? To destroy humanity, and usurp the thrones of the gods. They have their sights on Arthur, but they will fight anyone they catch... meddling.

Figured I'd throw some stuff in here as well.

Jackie's primary threats would be from Vilgax, an alien warlord out to conquer the universe by stealing the Omnitrix and reverse engineering it to create a shape shifting army.

The Hibreed, the first sentient species of alien that are slowly dying out and plan to wipe out all life with them.

There's also the incurseans, frog-like aliens bent on conquering the universe.

For individual antagonists, Jackie's got Dr. Animo. And vice versa Animo has Jackie as an antagonist.

Edit: I just remembered the Forever Knights, a secretive organization that hoards alien tech for unknown reasons. They have an over all medieval theme going on visually.