Hit-Point Increase - Your hit point maximum increases by an amount equal to your level when you gain this feat. Whenever you gain a level thereafter, your hit point maximum increases by an additional hit point.

AC - You gain additional AC equal to your spellcasting modifier. 

Detection - You can cast the Detect Thoughts spell and the Detect Magic spell at will.  

Truesight - You can cast the True Seeing spell twice per long rest. 

Expertise - You gain expertise in Insight and Perception. 

Force of Will - Aa a reaction you can cause a save you fail to succeed, cause a critical hit on you to be a normal hit, or cause a hit on you to miss. You can do these effects a number of times equal to your proficiency modifier, and charges reset on a long rest. 

Spell Mimic - When you see the full casting of a spell you can use your reaction to memorize it. Thereafter any spell that you've memorized using this feature within the last day, you can use an action to spend a charge to cast 1 of those spells at the level you saw it casted at. If the spell slot level is beyond your current maximum spell slot level, then you can only cast that spell once. Additionally, if you have the Keen Mind feat you can spend charges to cast spells that you've memorized within the last month. You can do this a number of times equal to your proficiency modifier, and charges reset on a long rest. Disclaimer - Spells memorized using this feature cannot be used through your normal spell slots and must be used via the charges described above. Additionally if you are a wizard, you cannot copy memorized spells from using this feature into your spell book, however if you see a spells formula you can memorize it and use the spell via this feature. 

Clairvoyancy - After you've recieved a longrest roll a d100. On a 1, you are blinded for 24 hours. On a 2 to 50, you'll receive an unclear vision about you or someone close to you that will come true within the next 24 hours. On a 51 to 80, you'll receive a vision about you or someone close to you that is a falsehood about the next 24 hours. On a 81 to a 99 you'll recieve a true clear vision about you or someone close to you that will come true the next 24 hours. And on a 100 you'll be able to almost bend the fabric of reality to your will by completely knowing everything that will happen to you for the next 24 hours or receive 1 use of the wish spell.