An Organized Mind is a Powerful Mind

After many years of study/meditation/prayer/(whatever else), you have honed your mind into a powerful tool. You have an excellent memory and can pick up on details faster. You gain an unfailing internal clock and a +2 on all intelligence and wisdom rolls. You also gain resistance to any mind-affecting debuff and Psionic attacks. This being because you know your mind better than the back of your hand and will quickly and rapidly mount a stalwart defense. Your control over your mind also means that you are resistant to fear or other sudden rushes of emotions taking over.

Your control over your mind gets better as you gain in level. you eventually start developing immunity to mind afflicting debuffs of a supernatural origin (spells and things of that ilk). The formula to determine immunity a spell level that meets or is below the value given by this formula: (((Your current level)/2) rounded down) -1. A helpful chart is included below.

1. level 1 | Immunity level = 0
2. level 2 | Immunity level = 0
3. level 3 | Immunity level = 0
4. level 4 | Immunity level = 1
5. level 5 | Immunity level = 1
6. level 6 | Immunity level = 2
7. level 7 | Immunity level = 2
8. level 8 | Immunity level = 3
9. level 9 | Immunity level = 3
10. level 10 | Immunity level = 4
11. level 11 | Immunity level = 4
12. level 12 | Immunity level = 5
13. level 13 | Immunity level = 5
14. level 14 | Immunity level = 6
15. level 15 | Immunity level = 6
16. level 16 | Immunity level = 7
17. level 17 | Immunity level = 7
18. level 18 | Immunity level = 8
19. level 19 | Immunity level = 8
20. level 20 | Immunity level = 9*

*Note at level 20 you gain absolute dominon over your own mind and are immune to any mind afflicting debuffs no matter the nature of the origin.

So this feat is fairly powerful and has some decent utility. Work things out with your table to tailor this for your table.