One of the most flavorful aspects of psionics in Dark Sun is Mindscape Combat. Published novels and short stories written in the Dark Sun setting used a fantastic “mindscape” where psionic combat occurs. Here are some basic rules to use Mindascape Combat in any edition.
Wizards of the Coast has released an Unearthed Arcana article called the Awakened Mystic. It appears to be a partial class called the Mystic with a few features from the class. The class seems to have some interesting mechanics and takes on psionics. What do you think of its use of concentration?
EDIT: They've updated it with the full Mystic class, up to level 5