Can anyone post a 'walkthrough' on how much training at each level of Psy Power/Defence costs? A wild guess, does it increase by 25 per level?
Yup. 25 gold per level for the team mates, and less for Duvalier, depending on his aptitude.
It may also be interesting to know when the attacks are unlocked by training in Character Upgrade's at Nameless One's (http://sinisterdesign.net/forum/index.php?topic=52.0).
for the hero its 15 per level
No, it depends on Aptitude.
25 per level for the hero, but subtract 15 per Aptitude.