Once a month we’ll do a Random Monster Mashup! This could take many forms – maybe see what happens when the monsters fight or team up, think about what kinds of circumstances might result in this situation, and even, if we’re feeling really creative, think about what happens if we stick these two monsters in a teleporter together and hit “SEND.”

The combination this month is interesting: Assassin and Arch-Hag. On the surface, these two seem to have little to do with each other. One is a skilled bringer of death who kills for money, and the other is an all-powerful fey creature who likes to ruin lives for her amusement. The Assassin’s methods are too direct and final for the Arch-Hag, who likes to drag out the suffering of her victims, and the Arch-Hag lacks the simplicity and directness that makes for a good Assassin.

That said, the way the overlap is a pretty simple one: they’re both problem-solvers. When you need to deal with someone or make trouble disappear, you can go to either one of these characters, depending on how much time you have and what you’re willing to pay. In gold or otherwise. The fun comes in seeing how these two methods of solving problems interact with each other.

For example, let’s say you want to kill a king. As one does.

You could hire an Assassin, who will get in there with subtle knifes and even subtler poisons. They’ll scale the walls of the castle in the dead of night and then sneak out through the service corridors they mapped out while posing as a servant. By the time the King’s majordomo knocks on the door of the Royal Bedroom in the morning, the body is cold and the Assassin is already miles away.

Or you could request the services of an Arch-Hag. Now, with her on the case, the King will die, but not right away. There’s a decent chance he will have to watch his family die first, one at a time, in decreasing order of how they ascend to the throne. A cousin first, then maybe a beloved nephew. Eventually the King’s brothers and sisters, and by that point, the King will be desperately be trying to find a way to protect his own children. But that won’t work. Not against an Arch-hag. Soon the entire bloodline will be gone, the King will be found dead of a stroke on his throne, and the kingdom will be delivered into chaos as a War For Succession begins.

Either one of those is a great seed for a campaign.

But why not both?

This King is so despised that you have people trying to kill him left and right. A faction of rebels in the kingdom pool their money and hire an Assassin whom the underground rumor mill says is the best in the business at reaching high-value targets. These revolutionaries deliver what little they have and ask that the deed be done as soon as possible so they can use the disruption to launch their own insurrection. They safeguard their improvised weapons and cobbled-together armor in the knowledge that a more egalitarian future is on their doorstep.

At the same time, a wealthy merchant, whose business had been upended completely due to one of the King’s petty rages, has decided that he not only wants the King to die – they want the King to suffer first. So they follow local legends and seek out the Hag, trading away their own most precious possession to do it. Maybe an eye. Maybe years of their life. Maybe even one of their own kin. Spite and hatred know no limits, and the Arch-Hag is happy to indulge.

Now you have two powerful forces working against each other and, in the process, making it almost impossible for the two to get the job done. The Arch-Hag’s reality-twisting magic keeps getting in the way of the Assassin’s plans. Guard rotations are changed, construction on the castle means that the sewer entrances are blocked, and there are workmen in every blind spot that would normally be hidden.

On the other hand, the Assassin keeps having to make quick decisions to escape notice, and some of those are targets of the Hag. A Prince stumbles upon the Assassin’s hiding place and needs to be silenced? That Prince was supposed to have fallen off the tower, only to land right in front of the King. Now his body will never be found, and the Hag has to adjust her own approaches.

And your Players are caught in the middle of all of this. Mysterious deaths, plots against Royalty, all pointing at something terrible about to happen to the Kingdom, but nobody truly understands the scope of what is coming. And if either the Assassin or the Hag succeeds, the Kingdom will burn.

What if you want to go the other way, however? Make the Assassin and the Arch-Hag work together, rather than separately?

A Hag-trained Assassin would be formidable indeed. Imagine an Assassin with access to the magic that comes with being part of a Hag Coven. Not only can this Assassin do what their other professional colleagues can do, but they would have access to spells such as Scrying – so they can know where their target is at any given time – Locate Object – to track that precious family signet ring their target always wears – or Augury – so they can tell ahead of time what course of action might be best to take. Their Hag sisters could cause chaos in their wake with their own malicious manipulations, moving people around like playthings so their Assassin can have a direct route to their target.

It would be an unusual move for an Arch-Hag, to be sure. They usually want to keep people alive and suffering, perpetuate their pain for their own amusement. But there are problems that can only be solved with a quick death, and having an Assassin imbued with Coven magic is about as quick as it’s going to get. For your Players, trying to stop a magic-imbued Assassin from hitting their target will be a whole new challenge, especially when they find out who the Assassin’s allies are. Sure, they could stop the killing, or even slay the murderer in their tracks, but now they have an enraged Arch-Hag to deal with.

The larger point is that a quick death and a slow one aren’t really opposites. They’re just options on the same menu, and they go together in different ways. When the Assassin and the Arch-Hag decide to work together instead of past each other, your Players will learn the worst lesson of all: sometimes evil collaborates.