So ... Level 12 elven whirling slayer barbarian, [here]

I'm looking to optimize her damage output - and more specifically on her offhand, which does NOT get her Str bonus. Since it's an actual damage roll, however, pretty much all other modifiers will apply. Her current build is playing around with Light Blades, but I'm not sold on that idea. I *am* sold on the +3 Jagged (whatever). Expanded critical range plays nicely with the barbarian's Rampage class feature. Plus, ongoing damage.

So ... light blades or heavy blades? Feat and gear suggestions are also welcome.

A bit more info:

I'm leaning heavily on Light Blades, primarily because there's a lot more feat support for them than Heavy Blades. Toss on top of that that one of her Rage powers blinds adjacent enemies. It seems to me that the flat bonuses from Light Blade Expertise more reliably boost her average damage than the larger damage die of, say, a bastard sword.

Am I right in my thinking here?

Sounds right to me. With a rapier for your main weapon (I'm thinking rapier and short sword as the combo if you go light blade), you're only down an average of one point, which goes away as soon as you get combat advantage.

I don't see where you get a lot more feat support for light though, heavy blades have just as many feats as light. I'll admit HB Expertise isn't as striker friendly as LBE. However, heavy does have the very handy Heavy Blade Opportunity, which would allow you to use Whirling Rend as an opportunity attack. I suppose how useful that is depends on how hard the your GM works to deny OA.

I thought about that, and one of my earlier builds made use of HBO. (I was pretty geeked about the idea of using Pressing Strike to keep the target from moving very far. However, in my experience in 4E pBp, Opportunity Attacks are few and far between.

I guess when I referred to feat support, I was looking at boosting damage.

Why do you suggest a short sword offhand instead of another rapier? The rapier has the best light blade damage die.

Two rapiers looks weird?

Also look to Spike Chain Training, costs you a feat but gives 2d4 damage and you only have to upkeep one weapon.

EDIT

Oh, you don't have Two Weapon Opening? Seems like a perfect fit for your Barbarian!

Actually, what I don't have is a DDI subscription. Where does one find Two Weapon Opening?

And I won't be using a spiked chain. The max damage is the same, and it has more consistent average damage, but I dislike the entire idea of the weapon. I'd go with a double sword (even after the damage nerf) before I'll do that.

However, if you take a closer look at the build, you'll notice that +1 Rhythm Rapier. +1 to her shield bonus to AC & Reflex when she wields it in her off hand. Unless there's a compelling build for heavy blades, I'll be keeping that as her offhand weapon.

RE: Two-weapon Opening

Meh. I'd rather have a flat damage boost for all attacks than another attack roll triggering off a crit. Even with the expanded critical threat with a Jagged Weapon, that feat would go unused for most attacks.

I don't believe Two Weapon Opening is useful for Barbarians anymore since the restriction to free action attacks. You already have Rampage, TWO is a wasted feat. In fact, I'm pretty sure that Barbarians (especially Whirling Slayers with TWO) were one of the major reasons for that ruling. Well, them and taclords. Pre ruling, I once did over 300 damage before my turn ever started with my epic whirling slayer.

You're right about dual rapiers, I just automatically looked for an Off-Hand weapon, not thinking that if you never make any actual attacks with the off hand weapon...

Rhythm Blade is the best off hand weapon enhancement ever. Especially since the enhancement doesn't matter.

You might want to get a feat that gives you more reliable CA, especially since that's a flat +2 bonus to damage. Also, two very nice feats with light blades: Nimble Blade and Light Blade Precision.

I would reconsider Superior Reflexes and Blood Thirst specifically. Light Blade Precision would apply to every attack, not just when a foe is bloodied, again assuming they are Large foes.

Your defenses are amazing for a barbarian..hell for anyone level 12. You should look at an elven chain shirt if you can afford it.