1. Illusions - Tanis casts them through eye contact, and plants the illusion within their mind. As long as the illusion is still in effect, she can use words or actions to manipulate the illusion. Her understanding is basically that she doesn't have to do all the work to make the illusions convincing. The subject's mind will fill in details and make up stimuli on its own if she gives the right push. This ability is augmented by hallucinogens, whether inhaled or injected, or if the target is already extremely willing to believe certain things. For example, someone who has heard rumours of Tanis' skill in battle and that she never gets hit, will be more susceptible to an illusion of her being too fast for them, or her attacks having greater range and speed than in reality. Conversely, an illusion where she suddenly morphs into a giant dragon will be too obvious of an illusion and seen right through unless someone believes she is a shapeshifter and not an illusionist.

2. Dreamwalking - This depends on Tanis' relationship with the subject. People she knows and are more willing to let her into their minds would only require her to be in a meditative state. If she were 'invading' someone else she doesn't know, she would need to sit in a circle of glyphs, and possess an item with a strong connection to the target. Alternatively, she has to be in proximity of them. Again, since the dream is the domain of the subject's mind, as long as they know they're dreaming, they can control the parameters of the dream better than Tanis. So the importance of her skill is to make the dreams believable and a passable substitute for reality.