Upon reaching 5th level, an antipaladin receives a boon from his dark patrons. This boon can take one of two forms. Once the form is chosen, it cannot be changed.
The first type of bond allows the antipaladin to enhance his weapon as a standard action by calling upon the aid of a fiendish spirit for 1 minute per antipaladin level. When called, the spirit causes the weapon to shed unholy light as a torch. At 5th level, this spirit grants the weapon a +1 enhancement bonus. For every three levels beyond 5th, the weapon gains another +1 enhancement bonus, to a maximum of +6 at 20th level. These bonuses can be added to the weapon, stacking with existing weapon bonuses to a maximum of +5, or they can be used to add any of the following weapon properties: anarchic, flaming, flaming burst, keen, speed, unholy, vicious, vorpal, and wounding. Adding these properties consumes an amount of bonus equal to the property's cost (see Table 15–9 in the Core Rulebook). These bonuses are added to any properties the weapon already has, but duplicate abilities do not stack. If the weapon is not magical, at least a +1 enhancement bonus must be added before any other properties can be added. The bonus and properties granted by the spirit are determined when the spirit is called and cannot be changed until the spirit is called again. The fiendish spirit imparts no bonuses if the weapon is held by anyone other than the antipaladin but resumes giving bonuses if returned to the antipaladin. These bonuses apply to only one end of a double weapon. An antipaladin can use this ability once per day at 5th level, and one additional time per day for every four levels beyond 5th, to a total of four times per day at 17th level.
If a weapon bonded with a fiendish spirit is destroyed, the antipaladin loses the use of this ability for 30 days, or until he gains a level, whichever comes first. During this 30-day period, the antipaladin takes a –1 penalty on attack and weapon damage rolls.
The second type of bond allows an antipaladin to gain the service of a fiendish servant. This functions as summon monster III, except the duration is permanent and the antipaladin can only gain the service of a single creature and that creature must either have the chaotic and evil subtypes or it must be a fiendish animal. Once selected, the choice is set, but it may be changed whenever the antipaladin gains a level. Upon reaching 7th level, and every two levels thereafter, the level of the summon monster spell increases by one, to a maximum of summon monster IX at 17th level.
Once per day, as a full-round action, an antipaladin may magically call his servant to his side. This ability is the equivalent of a spell of a level equal to one-third the antipaladin's level. The servant immediately appears adjacent to the antipaladin. An antipaladin can use this ability once per day at 5th level, and one additional time per day for every four levels thereafter, for a total of four times per day at 17th level.
At 11th level, the servant gains the advanced template (see the Pathfinder RPG Bestiary). At 15th level, an antipaladin's servant gains spell resistance equal to the antipaladin's level + 11.
Should the antipaladin's fiendish servant die or be banished, the antipaladin may not summon another servant for 30 days or until he gains an antipaladin level, whichever comes first. During this 30-day period, the antipaladin takes a –1 penalty on attack and weapon damage rolls.