Dartmuth Secret [Iconic]
Through a secret, deeply disturbing ritual, you have expanded the power of your mind over your body.
Benefit: You gain [Damage reduction] equal to half your Intelligence modifier instead of half your Constitution modifier. If you have at least 10 ranks in the Vigor skill, this [Damage reduction] is instead equal to your full Intelligence modifier. If you have Arcana trained but not Athletics, you gain a bonus to your movement speed as if you had trained Athletics.
Pick one of your tracks: you can use your Intelligence modifier instead of another ability modifier for calculating the benefits from all circles of one of your tracks. For example, a tactician who picked the shaman's spellcasting track could take this feat and base all aspects of that track on Intelligence rather than Wisdom.
At 5th level, you gain the ability to inflict a bizarre form of rust on most metals that spreads slowly of its own accord. As a standard action, you may touch a metal surface in a square within [Melee] range. While within 60 ft of a square of a surface touched this way, you may "look" through patches of the rust as a free action, allowing you to see out of and establish line of sight from that square. [Darkvision] applies when looking through these windows, but you cannot use any other vision modes you possess through them.