Couple of elements on the whole Dhar chat:
-Wielding raw Dhar is corrupting in the same way that wielding Ulgu is corrupting. In order to use it, you must think like Dhar. Which means embracing destruction and strife as a way of life, not unlike the Druchii, though in typical elven fashion they can do so without embracing self destruction entirely, a human doing so is more or less a Chaos Sorceror already and jumping off the slippery slope.
--Necromancy reduces this by changing the nature of the perversion. By wielding Dhar through Shyish tongs, instead of the purely destructive Dhar, interpreted through Shyish it is the refined arrogance and sundry flavors of domination that is rejecting the natural order of death and Shyish's fatalism. Necromancers of course, still pick up Dhar taint, but a constant across necromancers, even vampires, who are immune to the taint, is this arrogance to tell death to go take a hike.
---In practice, this gives them a large power boost because of how readily available Dhar is compared to every other Wind and the ability to exceed Shyish's boundaries.
---In theory, there is nothing keeping you from wielding Qhaysh through another wind safely. This wouldn't give a large power boost(because Qhaysh doesn't occur naturally, you'd probably suffer a DROP in raw power without a fuel, unless you were an elven Loremaster, in which case you don't need to do all this twisting), but it would widen your options.
----But nobody knows exactly how to do this because they lack the foundational knowledge. Nagash built his Necromancy off existing practices of wielding arcane winds through divine lores(or the reverse, I doubt anyone knows for sure except Nagash anyway). Nobody's going to try because it's a lot of work for no gain.
So, net assessment:
-Wield Dhar directly - No that's dumb, even if you don't get corrupted, it doesn't stop you from having to be a terrible person to use it.
-Wield Dhar through Shyish - This is probably going to explode because we've enough Ulgu arcane marks to make working the Shyish impossible anyway.
-Wield Dhar through Ulgu - This is going to still output Dhar into the environment, which is not really in our best interests, even after we figure out how to use it. No idea what kind of personality changes.
-Wield Qhaysh through Ulgu - This would normally be impossible because the process of experimenting would generate Dhar(which we've solved via the belt), we wouldn't have a significant supply of Qhaysh to begin with(which we MAY have solved via snake juice) and we wouldn't begin to know how to wield a Wind with another Wind(which we've a start via the Book). There's still whatever mental twisting needed to do so, but we won't know what until we try.
Now for less maddening debate: What DOES wielding Qhaysh through another wind do?
Shyish is Death. Dhar-Through-Shyish is the violation of death, using two destructive forces to cancel out(destroying death, etc) and approach eternity. Qhaysh-Through-Shyish is unknown, maybe rebirth, as continuance after death.
Ulgu is Shadow. Dhar-Through-Ulgu is unknown. Qhaysh-Through-Ulgu is unknown.
