Not got time to write this out fully today, but some early thoughts:
Lord level special character
CD lord stats (possibly a little better)
S3 -1AS flaming breath attack
2+ Scaly Skin
Aura of Darkness: -2 to hit modifier from shooting
Immune to all fire based attacks
Cannot be the general, cannot join units
Basically the fluff behind him is that the enemy would see a great black cloud coming over the horizon, with rolling thunder, lightning and flames etc. Minutes later (for added drama) they would begin to see in the cloud of darkness the outline of a Chaos Dwarf with burning skin, raining firey death upon them like an avatar of hashut.
Cool idea, it coincides very scarily with a book I read recently. Would he be coming on like a mining unit? or would he be deployed normally. You could right some great rules for the place where he would appear, being able to cause terror before the model arrives would be an interesting thing to watch.
I’m not entirely sure that would work, as you have to be within 6" of the actual model right? So he wouldn’t be able to cause terror before he arrives if he appears like a miner.
Being a flying creature he wouldn’t really need to appear like a miner, but being summoned from the earth somehow and able to charge (as a flying model) on the turn he arrives would be… awesome (but probably unbalanced)
What could happen is that the range for him causing terror is changed to 2D6" (either rolled each turn, or at the start of the game, whatever is better). That would get across the idea that fluffwise instead of looking just at him and getting scared (within 6", as with all other terror causing monsters) you see a massive cloud covering the horizon and know something bad is coming…
A fire breathing, flying, terror causing Chaos Dwarf is a cool start for an idea I think.
Hmmm… hope you don’t mind some random ideas Grim? This guy sounds fun, but part of me says you could really make something here. Just some possibilities for you from my deranged birdcage of a brain
1) Instead of deploying at the start of battle normally, the player designates a terrain feature anywhere beyond a 12" radius of the enemy deployment zone. Then the character arrives, able to use a flying charge move, on the basis of an increasingly easy roll (i.e. turn 1 =5+ turn up, 4+ on turn 2 etc). The nice thing about this is that the enemy will be sort of under pressure from the start, because they can’t exactly shoot the landscape to get rid of him. That would also fit with him being a single character unable to join units, but still be suitably nasty. It would also mean he can sort of rise out the rumbling, shaking earth in a fount of magma as he shifts the tectonic plates around.
2) Give his Ash Cloud effect a wider benefit - perhaps it confers a 5+ ward save against shooting attacks for all friendly Chaos Dwarf units within X" radius (6, 12, etc), or bolsters them in a fight (like making them all Stubborn). The player then has to choose between using him defensively, which is useful, or ramming down the enemies throat and hoping the terror and fire breath will do the trick. In fact, you could link the Terror and Ash Cloud effects together and possibly roll randomly as you are suggesting in your post.
3) As an even wierder idea, make it so he can spawn a swarm base of “Ashling” demon creatures each turn, maybe a bit like the skaven’s rat swarms? Then he can either be flown straight in to cause havoc, or wait a bit, generate swarms to bolster the battle line, and then slam like a small, angry, bearded comet in at the end of the game?
I have to say, as a long term fan of the comic book shadow character I am very dissapointed you didn’t want to do a Chaos Dwarf homage… imagine a shadowy chaos dwarf assassin with twin Inferno/Magma pistols, a long cloak, and a creepy laugh!