I'd like a new reason to play halfbloods, such as tough to find rares or even no find rares only found on half bloods (but don't go crazy, no turning them into farms specifically for rares).
At this point, I believe some folks still do AI3 for score and most do FGs for the 1k cards they give about 28% of the time. But for FGs, a lot of the cards are usable in various decks and the few remaining are sold for a nice profit to buy the upgrades for the other decks typically on cards that can't be won or are not won very often (think pendulums or towers).
I'd like half bloods to turn into a smaller stepping stone, such as going from AI2 to AI3, it doesn't take a lot of work to get a working deck and the decks are somewhat useful for early arena/pvp1 (sometimes pvp2 if going for speed kills).
Imagine an AI4 that (as somewhat suggested by other folks) that only has 1 draw and 2 quantra or even 150 hp, yes yes...or both.
I'd love to see shards and weapons (unupped) as the rewards for HBs that are based off of them using those things. The one down side is that most AI using weapons is either insanely difficult to plan a normal deck around, or very specialized such as Divine Glory. Of course, there are plenty of decks that can run circles around DG that isn't a DG only deck.