You gain the following benefits:

Psi Boost. When you take the Dash action, you can increase your Speed by 10 feet until the start of your next turn.  You can do this a number of times equal to your Proficiency Bonus, and you regain all expended uses when you finish a Long Rest.

Psionic Talent.  You know the Telekinetic Fling cantrip.  You always have the Thunderwave spell prepared.  You can cast it once without a spell slot, and you regain the ability to cast it in that way when you finish a Long Rest.  You can also cast it using any spell slots you have.  When you cast these spells, they require no Verbal components, and Intelligence, Wisdom, or Charisma is your spellcasting ability for them (choose when you select this feat)