I agree that it's a very strong combo, but I wouldn't push it to broken yet.So 1 rage attack + 5 attacks from the encounter = lose 18 health, add 54 damage. Trading 18 health for 54 damage is REALLY GOOD (especially when you then gain 15 brand new temporary HP). That much damage BY ITSELF is going to bloody an equal leveled artillery or controller, and that's before you add in the other 8d12 + 114 or so. So with zero critting we're looking at an average of about 220 damage on something I can flank (totally easy) that has 25-26 AC. And this isn't "average on a hit", because I only miss 5% of the swings I take, and thanks to Frenzied Berserker, the missed swing on Storm of Blades deals half damage, anyway. So we can safely assume that I'm nearly automatically going to deal 200 damage to a target with 26 or less AC. This will almost assuredly drop it, giving me access to swift charge. And this is all without the ungodly 5d12 + 1d10 extra on a crit, plus max damage, plus free attack for another 1d12 + 28.
We can go back and forth and debate about level 14 mobs, and elites vs. standards, and a bunch of other crap, but the point is with this combo you can unload 200 freaking damage basically any time you feel like it, provided you don't roll complete trash. "Don't roll a 1" stops working as soon as things become elite, or higher level, but an at-will buff puts it back in range. This combo is NOT BALANCED, and adding or subtracting a few points of Str or AC or Con isn't really going to change anything.
The question isn't "can you take an action in the middle of someone else's action?" its "can I take an action in the middle of my own action?" For example, a ranger cannot, after his first attack with twin strike drops an enemy, mark a new target before making the second attack.
edit: oh and 26(lurkers and artillery) is the low end of AC for 14th level monsters, with 30 (soilders) being the high end. All non-elites of course.
What I have an issue with is when people shift the goalposts. Your level 13 barbarian can't have +6 strength and +5 con, and he doesn't receive a +7 bonus for level...oh and we're assuming he's flanking too. Got it. You're also still not hitting AC29 on a one.
Even with that, I'll tell you that this character is pretty powerful, but he's also living on borrowed time. With 11s or 9s in all of his other stats, his AC, REF and Will are going to be terrible. He's also going to contribute nothing to the group in a skill challenge that doesn't involve athletics.
Beyond that, unless you're creating this character at level _14_ which is what I think you meant, you've had to play them to the point where they got this uber ability, with all of the weaknesses that low AC and defenses give.
So you've got a good character, but I'm far from thinking you've proven bloodclaw to be broken.

I agree that it's a very strong combo, but I wouldn't push it to broken yet.
The way I see it, 4e isn't balanced around individual one-on-one fights, it's balanced around the encounter. That combination requires you to spend an action point and an encounter ability. After you've done that, you might have taken out one or two opponents, but three or four will still be left and your best combo is no longer available to you. No doubt, you've made the encounter significantly easier for you and the rest of your party, but it still isn't a guaranteed victory.
That said, the linchpin in that combo appears to be storm of blades, and I expect that it will eventually go the way of the ranger's blade cascade and the fighter's rain of blows. If it does get errataed, the number of attacks may cap out at four or even three.
W
So you really think trading an action point and a daily rage to immediately take out between 1 and 2 same-level monsters is fair? Your call, I guess. =) Yeah there's four monsters left (maybe), but there's also 4 more paragon tier characters up before I get to smash something up again. There are never any guarantees, but I think the fact that no other character in my party can come even remotely close to my damage output says a lot.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.