Fan's Question: What is your hardest match-up and why?
[64AMD]ShowTime: The three best Undead players are so hard for me because of AOE and hero kill.

Fan's Question: What is your easiest match-up and why?
[64AMD]ShowTime: Orc, because they are weak and do not have hero killers.

Can someone explain to me why? They aren't any changes amongst UD's and Orc

Orcs played with FS i think. no bm abuse, different playing styles, etc.

Assuming we're not talking about Reign of Chaos which really is a different game altogether it is more than just different playing styles. Blademaster used to be bugged: you could not walk through units while invisible. Blademaster as we know it today only started being used after that was fixed, with the trendsetter on professional level being Zacard in the World e-Sport Games I (early 2005) I think.

Zerter still alive eh?
First off, windwalk wasn't bugged, they just buffed Blademaster by giving him 0 collision size. Just like they buffed his speed and damage. (thx Blizzard... morons)
And Blademaster was used before WEG1 because WEG1 spelled doom for the short period of Orc owning elf, after mass summons got nerfed blade/raider/demolishers raped the usual elf 2 random heroes hunts/dry. Then came WEG1 and mass dotts by MagicYang and Moon. Mass dotts was meant to counter the Blademaster to begin with.

backstab dmg from ww was nerfed from 70/100/140 to 40/70/100 or smthng like that

Yes, they nerfed the backstab damage AFTER they buffed it. It's funny, back in the day Blademaster was one of those heroes that got a "This hero exists, please use him" buff in every patch. Much like Bloodmage, comparing his stats and damage to other heroes is funny cause he kills a Dh at level 1 iirc.

I never bothered to check but is that actually true? I read someone saying that BLM has the 2nd highest dps in the game once o_O Seems hard to believe.

after 7 years of playing w3 i know only one buff on blademaster and that was running through units in windwalk, and instead of buffing bm as you say orc get nerfed fs
zechs, bloodmage got fast attack speed i think

check the patch.txt, he got lots of buffs.