The reason I think its a virus is because its only on one side of the leaf. That is one of the symptoms of it is the markings on one side. I don't handle live tobacco, but i do use tobacco products... like blunts :stoned: I guess, the soil mix could be burning the plant, but i would expect it to be all the leaves, both side of the leaves. This thing looks healthy except for the pictures shown. All the other leaves are looking great. Only thing is it has been having weird node alternations. Instead of the typical symmetric growth it should be showing, it has 2 nodes on one side then it will go symmetric then one on the other. very odd.