Dorastor is a fun place. In our shared-GM RQ2 campaign, I often set scenarios there. In my RQ3 campaign, much of the campaign was set in Dorastor. My recent River Voices campaign had a few things in Dorastor.
What I normally do in Dorastor is not make it ultra-deadly. By which, I don't mean make it just another wilderness campaign or chaos nest campaign, but instead make some bits fairly straightforward.
So, the bits of Dorastor near Riskland are fairly safe. Sure, they have Broos, Scorpionmen and Ogres but that's normal for a Chaos Nest. Areas around Forts are patrolled and safe, or as safe as anywhere in Dorastor can be. Anyone holding a Ralzakark Token can be sure that if they present it to a group of Chaotics, they will be left alone, or maybe not.
So, lull them into a false sense of security as to how dangerous Dorastor is. Have a few scenarios where it is just like a wilderness or chaos nest. Clear a few chaos caves out, fight some Broo, find some human-looking Ogres, that sort of thing. Then hit them with a Monstrosity of some kind.
Monstrosities can be of varying kind:
Chaos Monster - An random Chaos Monster that is utterly gross, imagine Cacodemon, The Crimson Bat, Cwim or something equally as dangerous. Have it come along and scare the bejaysus out of the Party and let them escape.
Intelligent Chaos Foe - far more dangerous than the Chaos Monster, these are intelligent and well-organised Chaos Foes. Not the personalities, but perhaps a Rune Lord or Priest of a Chaos Cult and companions. These should be used to fighting and might be hostile to the party.
Personality - Far more dangerous than an Intelligent Chaos foe, these are the named people of Dorastor, Ralzakark, the Giant King of Never Dead, Queen of the Tower of Lead, anyone out of the Dorastor or Lords of Terror supplements. These may be friendly, may be hostile but are always very dangerous.
Terrain Feature - There are some bad places in Dorastor, Ghost dirt, Slime Pools, Ash Flats, Rolling Hills, Acid Lakes and so on. Be as mean and nasty as you want, after all it's Dorastor!
Ragnaglar's Breath - One of my favourites. Ragnaglar's Breath rolls around Dorastor in various forms. Acid Rain, Fear Storm, Mist of Madness, Poison Cloud, List Wind, you name it you can have it. Basically, it is a wind or cloud or weather that is incredibly nasty.
Each area of Dorastor is dangerous in its own way. Poisonthorn is full of nasty, non-chaotic but evil human-hating elves. Hellwood is full of Chaos-embracing elves. Both Poisonthorn and Hellwood are full of nasty, warped, hungry plants. Slimestone has the Gorpgod, a gigantic gorp that just rolls over you and absorbs you. The Tower of Lead is full of vampires and other undead. Ash Flat is full of ghosts. Some places have broos, some ogres, some Telmori, some scorpionmen. make them all dangerous and difficult. Leaving the PCs stranded in an area is fun, watching them fight their way out is much more fun.