Blackguard: Summon Fiend [Duration: 1 Round / Blackguard Level]
• 1st – 14th Blackguard Level
• Succubus Warrior [Chaotic or Neutral alignment]
• Erinyes [Lawful alignment].
• 15th + Blackguard Level
• Balor Lord [Chaotic or Neutral alignment]
• Infernal [Lawful alignment].

The Epic Fiendish Servant feat grants the fiend the following benefits:
• Duration is doubled
• Strength +4
• Armor Class +1 / Blackguard Level
• Regeneration +1
• Bonus Feat: Improved Evasion
• Spell Resistance = 5 + Blackguard Level

It says that you need to get a book from a DM to get the Epic Fiendish Servant. Well I wondering if 19 levels of Blackguard is good enough to get the book?
I plan on going 10 Cleric, 19 Black Guard, and then 1 more cleric on my last level.
Will that be enough to get the book?
Or is it just a RP reward? Or both a level requirement AND RP reward?

Thanks!