Understanding the Threat…
When some strange new creatures appear on the fringes of civilization, the kingdom is at a loss for what to do. At first the bizarre, serpentine creatures are easily repelled, but they quickly start putting up more resistance and becoming more aggressive. While once content to feed on forest creatures and the occasional livestock, recently a village was attacked and most of its inhabitants taken away for food.
Traditional means of fighting the creatures, which have come to be called slivers, have failed utterly, and now the king is starting a new tack. The court’s alchemist, and the king’s closest adviser, Tarangus Blaque, has been tasked with researching the creatures to find out how to get rid of them once and for all.
Having worked with the PCs before, and knowing this job will require reliable people, Tarangus sends for them personally. His first quest is a simple one; they must only capture one of the creatures, preferably one of the smaller ones (a sliver drone).
After the PCs acquire one of them, Tarangus studies it for a while, before deciding he needs a more potent specimen and sends the PCs out once more. On the bright side, Tarangus has concocted a salve which, applied to the crest of the creatures, should incapacitate them.
This time, it seems as though the slivers were expecting the PCs and set a trap for them. When the PCs do manage to acquire one of them, if they tell Tarangus about the trap, he will be quite surprised. He does not believe such creatures are capable of such complicated tactics; there must be a more intelligent mind guiding them.
Eventually, he discovers that the slivers communicate and identify each other with a specialized gland. If the PCs can procure more sliver drones (one for each PC), he believes he can make a “disguise” which would allow them to enter the hive and explore further.
He gives them some more of the sedative he’d created to aid them and accompanies them in their task. This time, the PCs discover that the slivers have adapted and are no longer affected by the sedative, complicating the task once more.
When the PCs capture the requisite slivers, Tarangus creates their “disguises.” Essentially, he takes the gland of each sliver and puts it in a small phial filled with a preserving compound. These phials are hung as pendants from each PCs neck. Finally, he warns them of two things:
1. Even preserved, the glands will not last for more than about an hour.
2. If, as he suspects, a more intelligent creature leads the slivers, it will likely be able to see through the disguises. They should be careful if they discover the leader and avoid being seen by it.
Tarangus gives the PCs a large barrel filled with a special blend of his own explosives. Their final task is to find somewhere within the lair to detonate it which will cause the most damage to the hive, and to determine if indeed there is a leader. If there is, the PCs should not allow the vile thing to escape.

Oh yes I can totally work with that I love it!!!! But I will definitely have to have more slivers. Wouldn’t crystalline just be a terror? lol
Well, they’re fun to make yourself, and I plan on making plenty more (expect, at the very least, at least 6-8 more over the next two weeks), so different kinds of slivers isn’t a huge problem.
Actually, I kind of like the idea of starting the slivers off as a very basic threat, maybe even just drones, and then they develop defenses. e.g. the villagers start burning the slivers, so the slivers develop new ones which grant fire resistance.
I think with a crystalline sliver, I’d probably give all the other slivers a bonus on saving throws. Not being able to be targeted by spells would be pretty unbalanced, I think.
Or they could redirect incoming spell to themself.
This time, the PCs discover that the slivers have adapted and are no longer affected by the sedative, complicating the task once more. <—-A “cure Poison” sliver!!!! Damn they are smart
One thing that I thought up was to abuse the whole damage resistance set of rules that’s in DnD to counter act magical attacks. Of course you don’t want to go overboard and knock out like 10 points of damage that a wizard is able to do, but maybe see how a resistance of maybe 5 or 6 (base it around the caster’s Int modifier possibly) would work for the slivers evolving into magical immune beasts. This follows with their “crap, gotta find a way to stop fire from hurting the hive… ok, fire resistance is good to go” type of thinking when they run into something new that they haven’t dealt with yet.
For another example, the Armored Sliver would be a good one to come up with in response to a rogue or fighter laying waste to a number of slivers in an encounter, have it give an aura that gives a 1 power bonus to AC for all the slivers.
MTG has so many possibilities when you try and throw the creatures into DnD =D