You can use your Intelligence in place of your Charisma for any rogue attacks, talents, or powers that use Charisma (e.g. shadow walk and slick feint). You also gain two extra points of backgrounds to spend on knowledge-related backgrounds and gain a +2 bonus to skill checks involving traps.
You gain a +1 bonus to Mental Defense.
Once per battle, reroll a save against an effect from an attack that originally hit your Mental Defense.
Your once-per-battle save reroll is now once per save.