The TLDR 2H Barb

That must be new because affix pool table says:

min item level 82, and all barb weapons
So maybe something here is new and I dont know about it? I admit last time I rolled one was on axe.

how can i boost my damage further after getting a yaggai's? is going for -light res craft a good idea? my attack rating is as good as it gets

It would boost damage but, note that cold also would (gaze), and wolves wont proc off stormblast, beacuse its 100% lightning damage skill, doesn't proc doom.
You are basically dealing bunch of different damage, stormblast proc every hit, deathgaze from attacks (cold/phys) fortress is phys, and to every phys you add +flat phys from wolves curse. Adding lightning pierce will ONLY boost stormblast portion of that full package of damage, so its some fraction of it. Not ideal way to scale dps.

You'd get more by getting just more ewd, strength, use like wolf druid set belt + chest combo, stuff like that. Yaggai is good item on its own, but it is sort of noob trap, as axe skills aren't lightning, and you spread your damage to different elements. It is still way better than TU labrys, even without considering any of it. But it is difficult to scale optimally.

Thanks. I switched to axe and after 3 shrines i got mark of the wild oskill. By the way why you dont admin life leech in weapon instead of mana on strike? I orbed it on weapon and put life jewels in armor rw and its pretty good. I dont need any heal potions in "normal" uber areas i only have to use some in some uber boss fights.

This is designed to beat bosses and get charms, not for farming, and for those life leech is useless for most part.

The affix list previously also only said "Barbarian weapons" yet I never got MotW on anything but axes and people said it's on barb axes only

Playing 2h barb, finally saw this guide. The only surprising part - no points to dex? . Why, you still need AR, during leveling too...and no points to daedalus...

1pt daedalus is very weak, it scales off hard points, increasing formula. Max it or ignore pretty much, imo 1pt isnt worth 5 points. I already explained skill choices couple of posts back. Old version of build went daedalus and it was significantly worse.

Any advice on killing Valthek? This dude seriously chaps my ass... I get maybe 5 purifies before I get locked out. What am I doing wrong?

That fight has nothing to do with build, you use completely different gear, so it roughly the same for all chars.
Key is proper movement, the way I always did it was to bait his jump, hit him with the spell and immediately run away. Repeat that until he is dead. Takes some practice getting used to it.