Fixed2. In several places you have DC 10 + 1/2 Class Level + Charisma Modifier. This should really be DC 10 + Class Level + Charisma Modifier.
So keep it the way it is?3. Belial seems more powerful than Fierna until 10th level, at which point the ability to sacrifice a spell slot to heal spell slot x 10 hit points becomes pretty awesome assuming arcane entry, but not really broken in any way.
I think I'm going to change it to three times per day the disciple can use that spell, as they don't have caps besides the fact that the boni fade after one round.4. The only abusable ability is the 5th level one. It's super easy to get ludicrous saves with it. I don't have my BoVD or Fiendish Codex or wherever the Sadism/Masochism spells come from, but do they have limits to the bonuses they can grant? I'm not sure it's broken, I'll have to think about it.
dawnsolara- fixed the wording in Path of Belial/Fierna. The Sudden Metamagics do stay once per day in their description. I'll tone down the sadism and masochism spells.