First of all, Death Prophet is not a carry.
Second of all, Swiftblade (Yurnero) is not an efficient hero unless the other team is a pug or very disorganised. He fares quite well as a ganker and stealer mostly because a lot of people can't estimate damage values and do proper risk assessment when taking up a lane.
But if you look at DotA pro replays - and I highly recommend TeG's matchups for this - you won't see Yurnero getting picked. Basically he's very fun to play and a pretty neat fragfactory but I wouldn't take him in a clanwar roster under any circumstances, and I doubt there are any real clans out there who would.
Thing is - he doesn't get gargantuan amounts of DPS, nuke potential or disabling end-game and his ulti is negligible in stacked groups. He's not really powerful in lane control (unlike more conventional control and gank heroes like Valk (Mirana), Night Hound (Rikimaru - Stealth Assassin) or Arachna (Traxex Lite). He doesn't even become a finisher unless someone feeds him and that won't happen in anything else than pick-up games.
kc ranted: "By the way, whoever recommended to me mask of madness, that was a bad idea. I got whispering helm, but seriously the -80% attack speed from her orb is just too good to replace so I sold it. That thing shut antimage down. Lothar's is also kind of a crappy choice. Everyone gets it for the easy escape but you shouldn't ever need it and it's super expensive for what it does and doesn't help in teamfights.
Since I never play Drow (I do play Viper sometimes) I was at a bit of a loss as to what to get. They didn't have nukers so I didn't go shaman's headdress. I just went 3Wraith+Vanguard+STR Treads+Crit+building butterfly at the end of the game. It's weird, in DotA I have no problem coming up with builds on the fly, but in this game I'm always like "uhhhh....let's see, what is there"
I recommended mask of madness because it's the best attack modifier you can get if you turn her into a carry. It actually overlaps with webshot so you can apply both the slow and drain life at the same time. And you got the wrong item: it's Elder Parasite, not Whispering Helm, that's the MoM analogue in Hon. As you might have noticed she doesn't have a fat health pool or any healing possibilities, but at 1.6k (around the time you actually become an asset to the team) you can 1v1 any other carry with drain life and you will win because of your innate slow and lifesteal.
And Assassin Shroud / Lothar is the most obvious escape choice. Unless they have detectors (Tree, Bloodseeker, Scout, etc.) Lothar will get you out of dozens of sticky situations. Trust me, played Arachna for over 25 matches and tried all kinds of stupid builds people posted on the forums, Lothar made me carry the game about half the time.
You don't need Vanguard because in most HoN setups you will swallow more than 1.6k magic damage, and that is literally unavoidable. If there are DoTs on you, sure you can dispel them with the carapace but most fights you will get into without a backing team include stuns (which you can't disable) and nukes (which you won't have time to prepare for). That's where Lothar comes in.
The game is less flexible than it seems unfortunately
I'm a bit annoyed with experimenting different builds and item setups for hours before I actually get to a very rigid conclusion.