Mindwarping is an alien power used for evil on WB sci-fi series Roswell.
This is a power unique to Tess Harding. With it, the user can manipulate a persons mind for various effects. The most prime use of it is creating illusions that can either be so realistic that the person thinks its actually happening or to the point of just seeming like daydreams or fantasies.
This abilities' prime achievement is to create illusions of visual and audio perspectives. It has slightly altered the vision of something or created a complete illusion of nothing that is there. Tess has been able to create illusions that hide something and/or someone from a group's vision by making them invisible to their eyes.
This abiltiy has also been able to acheive perform limited mind control like when she forced Alex to decode the Book of Destiny and forced Kyle to take care of Alex's dead body. Victims of this seem to go into a trance and will usually remember what they've done; their memories would have to be supressed. Tess has proven to be highly skilled at this ability, having had mind controlled Alex once, which had lasted for 2 months.
She can also suppress, but not erase memories. During a discussion Kyle referred to this as "brainwashing". Tess also seemed to be able to suppress or induce memories and emotions like when she induced Max's slight attraction to her into a way to get him to sleep with her, or when she suppressed (but not erased) Kyle's memory of her killing Alex or him taking care of the body.
As demonstrated with Alex, Kyle and Amy, once Tess removed/supressed their memories, 'new; memories were created. It remains unkown if Tess herself created these 'new'/ fake memories or whether through the help of her mind control abilities, she merely instructed her target to create their own 'new' memories, or if she had given a general description of their 'new' memories allowing the victim/target to create their own.
It should greatly be noted that repeated use of mindwarping on one person, without giving their brain time to recover from the damage, can be lethal to the victim. This is how she killed Alex. It takes a lot of time for the power to cause this much damage to the brain as it took months of mindwarping to Alex's brain for it to become so stressed and damaged that it killed him. It is unknown how he died from it but it was possibly to the same effect as a brain tumor or the like.
When tortured by The Skins, Tess' powers evolved to the point where she could bring her illusions to life resulting in a high powered blast of fire, rushing forward killing the skins. After the destruction she admitted she only tried to create an illusion of fire but it became real. She showed skill in this power; she was able to send the fire rushing past the Pod Squad without harming any of them but killing the skins.
It is possible she blew up the FBI building the same way and also possible that she killed the scientists monitoring her child with advanced mindwarp because the movement and vision of the situation was like a mindwarp. As Tess' power of illusion had been brought to life, it is possible that she demonstrated the ability of Projection, the ability to produce something through the mere power of ones mind.