Apostate is no default melee or caster cleric with some special evil SLA. He doesn't need Aura of Negative like PM or Negative Energy Burst. Because Apostate - it's special mechanic of battle. You must be in melee range, making cleave damage to curse (Enhanced Curse III) all around and then use Prayer, Bless or Bane for buff/debuff and then Inflict Wound for damage/selfhealing. This is one position and we need ask developers to reveal this strategy. But not to become new divine PM. Apostate need new source of curses (and may be new types). He need some kind of Cleave for his tree. I prefer use Wood Elves, 3 levels of Paladin, Iconic Aasimar or PDK for two-handed favored weapon. Even if apostate can't kill anybody with negative or evil bust - he can use his weapon