Imagine that but with Warp Talons

Just exchange AIDS for super AIDS in the equation. And add gonorrhea for good measure.

Imagine what Isha has for one second but gets it again because Nurgle keeps feeding her the virus's from his pot

But in the end everyone "desires" power, they may not come to Slaanesh, but they still desire it.

I said Slaanesh. That is by far the chaos god I would have the hardest time resisting.

Judging by the real world, I think Slaanesh would give Khorne a run for his $ too.

I don't think that it is allways a Slaanesh indicator to "desire" something.
As you can desire things like lust and pleasure, obedience and punishment, perfection and beauty, which would or would not bring you on Slaaneshs path.
But you can also desire things like hope, might, knowledge. In those examples, the term desire is relatively loose and does not allways indicate "Slaaneshs Path"

I probably took your post way too serious, but I wanted to state my opinion about that (I struggled alot, because my english is bad today)

Blue bird guy, go bird guy.

Tzeentch is the true Lord of the Pantheon! He offers enlightenment to those worthy and will be the final victor. For what sentient creatures doesn't have ambition?

But your god could change your victory to defeat on a whim what god would turn on his followers just because you are a thread in the stings of his playthings.where as my god just asks for one thing and one thing only which is that we shed blood in his name and that is what we do.

I think that's true to a point to be honest, but the sense that someone desires something corrupts the worship to that god (even by a small amount) thus feeding Slaanesh as well (this is one of the reasons the other gods are growing jealous of Slaanesh's steadily increasing strength).

I should imagine that this is how Marks work as well, as it places that god's 'ownership' onto the mortal and he gains strength from pretty much all that mortal's emotions, thereby circumventing the usual limitations of mortal emotions being split up and fed between the gods separately (because I don't think it's possible otherwise for wholesome feeling for something that isn't driven by other motivations, like you said, we are pulled in many, many different directions), but it costs the God something as well, which is why 'lore wise' we don't see every Chaos worshiper marked.

This is just my own personal musings (and if I worked for GW hellsyeah I'd make it official) on the topic though, because otherwise there is no real benefit for a God to Mark someone as far as I can see.