Do not look here said:I can't agree with you on the Mumiyo part. As you've said, Khergits have abundance of spices, so I actually believe that it has almost no downsides at all. From what N0ught said, once player tries it, he has to either hoard a small supply of it every now and then or move his lazy ass a bit more often. Really? For that price, with random chance of tearing to pieces a caravan that would carry me "free" mumiyo, I know I will be using it.
"Withdrawal syndrome" isn't even that impairing, it's not like you'll have to order your abominations to carry you to nearest bigger trading center, at most it will force you to hold up with leveling up (if you stumble on leveling up), cause of skill-capped abilities, until you'll have another portion of mumiyo ready. Reward isn't that great either (although, again, it will help with leveling up) and, frankly, I like the idea of mumiyo more for its RP-ing value than actual gameplay value.
About the manticore - fair enough. I just adore that winged design of them and would like to see some more mounts in that spirit.
About Mumiyo, I couldn't have put it better. It appeals for rp, and really a net -1 to all attributes is not that much to deal with until you get more... yes more... more... *ahem*. And if you don't want to get more, it's still not too bad.
I wanted it to be similar to "the spice" from Frank Herbert's Dune saga... quote: "it wont even kill you, unless you stop taking it." I had actually considered making withdrawal lethal. I thought that would be too much of a gamekiller though.
About winged mounts: I have tried to avoid them for the most part. The moth "flutters" presumably; the undead mounts have vestigial wings only. For the sake of the argument "this mount should fly" I make compromises.