Diffusal wind

Is DB good on wind ? +20 agi can help the atack speed when no ult, +6 int is sick for a cheap core item, also it has a 60%slow dat has great synergy with ult and general gank, also the purge grants alleria MOAR utility
And for the last, MANA BURN, with her ult it destroy the enemy mana pool in 3-8 sec, that is the main reason u buy difusal on wind
What u guys think ?

I don't know much about wind, but i think you would need an aghs for that to work with your ult (i think). And then, i feel that deso is really good on wind, but they don't stack.

Personally, I don't grab items such as Deso or DB on Wind because I play her more as a evasive character while buying support items. Carry Windranger is something that not many people do because there are better heroes for that role. She need's aghs and a core item to start becoming a carry so really not advisable from my perspective.

to get an item you should be making full use of it, wind ranger makes no use of mana burn or a purge so simply put its a bit of a waste, better off spending your gold on a more useful item. As wind yes the slow + ult could be good but for the same cost you could get a far better item. If your playing support...well you have to buy other stuff, ganker basically you just get e-blade+dagon=game and carry you just get damage stuff like maelstrom because it just works better. As a good wind if you going to put a shackle on you won't need to slow: good shackle-ult-lighting goes everywhere and everyone is dead. Its viable yes, but there are just better items

yay new icon, must post everywhere Rune of Double Damage

On semi-carry/damage based Windrunner, I think the best setup is Phase/Drums/Maelstrom, built into an MKB for direct right click damage.

She has great range and attack speed by default, so to fully utilise that you need high right click and MKB allows you to prepare to counter the 1-2 Butterfly pickups usually found on the enemy team.

Phase Boots
Drum of Endurance
Maelstrom
Monkey King Bar

Obviously the above is based on you playing a semi-carry Windranger, rather than a support/utility.

why drums? also AS of maelstorn is wasted
i would do ...
[Phase boots]
[Medalion of Courage]
[difusal blade]
[blink dagger]
[Aghanihn scepter]
also wind benefits of mana burn, because she is weak to magic damage and difusal + ult destroy the enemy´s mana in about 4 second (ik: shackleshot)

The AS is not wasted, its active whenever you dont use ulti.

Also you proc lightning like crazy when using focus fire.

Maelstrom is good on her because it stacks so well with her ulti. (The procs do full damage+you have max attack speed.) However I usually offlane or mid semi carry and I think it is best to just save an extra 2000 and get agh. As a semicarry rather than support you should have agh by 20. After that I recommend a damage item such as deso, MKB, crit, or diffusal. Wind is extremely situational so I would not build diff on her a lot but if the enemy carry is a clinkz, mirana, slark or other slimy, evasive char I would get. (Agh>deso>crit at 30=gg)

Actually, in my opinion getting orbs on carry Windranger is a bad idea: let's say you buy a Desolator with 4100 gold, you then have to buy an item worth 4200 gold to make it work with your ulti. With all that gold you can get a Scythe of Vyse and a Demon Edge, which not only give more damage (35 + 46 compared to the 60 + 10 damage from Deso and Agh's) but also scale better into late game - since the negative armor of the Desolator doesn't do much after Cuirass and Vlad's are purchased by the enemies - and have an invaluable active ability. Counting the damage reduction, you'll have less damage with your ultimate before completing your MKB/Daedalus, but you'll have a Hex and more flexibility, since you can turn your Demon Edge into either a Daedalus or a Monkey King Bar.

My carry Windranger build would be something like: Phase Boots, Force Staff, Scythe of Vyse and Monkey King Bar/ Daedalus, maybe substituting the Staff with the Maelstrom (haven't tested it that much yet). Also, why building WR as a carry? Well, she doesn't offer much utility as an off-laner (seriously, I haven't seen a good off-laning WR in ages, not after the laning phase at least) and has no reliable spells as a support. Also, find me another carry that can build a Scythe of Vyse: they're in fact very few.

Back on topic, I don't think Diffusal Blade is worth it: I've already explained why I don't like orbs, plus a Deso would be better. If there's an INT Hero that can make good use of this item, it's Nature's Prophet, but even then I'd only pick it versus a Warlock or Omniknight.

Or you could simply Auto-Attack then Focus Fire... 8{3

This does scale better Late Game, but if you want to win before 40:00, Desolator is the better choice.