Demonslayer Favored Enemy

At 1st level, a demonslayer must choose favored enemy (evil outsider). At 5th level and every time he advances his favored enemy bonus, the demonslayer must advance his bonus against evil outsiders. In addition to the normal benefits of favored enemy, a demonslayer gains a bonus equal to half his favored enemy bonus on saving throws against spells, spell-like abilities, and supernatural abilities of evil outsiders.