I concur; the class has a lot of things that need testing because they feel pretty powerful compared to what exists now, but Howling Blast isn't one of those abilities. If anything it's actually pretty awful at the level you get it (compared to a 9th level maneuver of spell) so the least I would do is make it Fort for 1/2 instead of Fort negates. Even the ability to spam it as much as four times in a single turn doesn't make it too exciting (you have to work awfully hard to do such a thing, anyhow).
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As an additional note, it seems as if right now Death and Decay can deal damage to you while the other AoE abilities cannot; might want to change the wording one way or the other (leaning towards "no self-damage" although DnD is pretty strong).