I don't think we know this for certain. Unless you have a quote that I am missing (possible I admit). The true nature of the DO is very poorly understood at this point. I think the idea that Rand shared Moridins TP is plausible. Obviously its not confirmed and we don't know for sure until the next/final book, but the DO=TP does not in my mind make it impossible that Rand took TP via Moridin. Even if the DO is somekind of energy cloud, that does not make it impossible that he gave some of that energy to Moridin, only to have it flow to Rand also.



I am not suggesting that they are only linked through OP, obviously they do share physical traits at this point. The hand is one example, and Moridin also mentions that he feels tired constantly and wonders if its him or Rand, (Rand was mentioned being tired in the same way earlier). The whole philosophical though about Creator being a gardener was also most likely from Moridin so their minds/thoughts are merging too. No doubt this helped Rands insanity. Infact the thoughts Rand has about creation at the end of TGS could almost be coming from Moridins mouth.

What I am suggesting that its not just body(hand/tiredness) and mind(philosophical thoughts) that are connecting, but ALSO their intangible power connections. If they are merging in all other ways then why not in that way too?



Maybe, but unlikely. The cases where Rand got sick without using the OP are rare. Only a few cases. If Rand got sick everytime Moridin used TP, he would be constantly sick. However if it happens only when Moridin uses OP (which he no longer does) then that would explain much.

Also, you are forgetting that it is not just nausea/dizziness that comes with the OP-sickness Rand is suffering from. In a lot of cases Rand also actually sees Moridin during the moment of dizziness.



That is not the only time Rand uses OP, and the face of Moridin appears in his head at the same time as the sickness. I doubt very much thats a coincidence.

I should also mention that we get a description of the type of sickness Rand feels from the conflict between his wounds, and it does not match the description of the OP-sickness.



Quite different. He feels pain but no nausea. No, I am convinced that the dizziness and sickness that comes with OP is indeed caused by the balefire link. That is why Moridin has abandoned OP. He may have wielded it a couple of times (the few times Rand got dizzy without channeling), but now he has gone TP only to avoid the nausea, and it should be added that since then Rand has not got sick without channeling himself.



I don't believe Moridin does use saidin. Infact it is even said in the books. As I said earlier, Demandred mentions that Moridin would have had to have used TP exclusively since he last saw him. But the way he says it implies that this is new kind of behaviour and Ishy at least used to use both. So why had Moridin gone TP only?

The possibility he cannot (easily) use OP anymore due to the link is good explanation to me. Rand has no other choice and so he has to suffer the horrible sickness everytime, but Moridin does have the choice of side-effect free TP. Moridin only gets sick when Rand uses OP, which makes him furious.