In pathfinder Tales character deck there Are cards that have card type Devil form...
What Are They and how Are They used? For some reason I have not seen rules conserning those cards...
The devil form cards are part of Radovan's suite of cards. See the first power on his base character powers.
They're sort of like the cohorts for witches/summoners (but not exactly the same). Each affects his abilities during the game, allowing you to customize his powers to the scenario (within limits).
Many thanks!