I think it depends on what he is going for. as it stands, the class is a solid Tier 3. Turning him into an arcane cleric with blood maximizing spells would probably bump it up to Tier 1.
Suggestion: Blood summoning sounds great, but what about making a limited blood summoning spell list (Like Summon Undead X or Conjure Ice Beast X). It could be something like "Conjure Sanguine Servitor 1-9." Heck, by mid levels you could probably summon vampires!
I dunno, I mean the cleric gets heavy armor proficiency and auto-ignore somatic casting, with a much wider spell list. I don't think this class could become Tier 1 without branching out more.