Do you think this card solves the issue of taking damage when facing aggro decks? After all, it does the same amount of damage as a hero power, while not offering healing or taunt to resist the aggressive minion push. I think Vulgar Homunculus fits this niche of anti-aggro/spellstone upgrading much better than Kobold Librarian. We also can't forget that cards like Dread Infernal and Abyssal Enforcer should upgrade the spellstone as well! While I agree Kobold Librarian is good value, I think in a control warlock you want 1) late game value 2)anti-aggro (including healing) and 3)demon synergy for Bloodreaver. I don't think Kobold Librarian offers any of these, and draw power isn't really necessary in a control warlock decks. None of the current lists run any card draw because the hero power substitutes for draw cards, not the other way around.