Do I get to deal an additional damage to each of my opponent´s capital sections when I use Offering of Blood with Hellcannon Reserves in play?

In my mind the wording " each section" could equal " more target´s "

Basically, if the card doesn't contain the word "target," there is no "target" for the purposes of Hellcannon Reserves. Blood Offering reads "each zone" just like Nurgle's Pestilence reads "each unit." No target in either case, so no bump to the damage.

Check the sticky at the top of the forums for a link to unofficial rulings; the ruling on Hellcannon is in there. http://deckbox.org/forum/viewtopic.php?id=232