November 1, 2012
Starting- Quelling blade and stout shield will allow you to out cs most opposing mid heroes, and stout shield will allow you to take some harass early on to score last hits.
Early- Complete your poor man's shield ASAP, Then start towards your red boots or if you think you can rush out a quick blade mail under 10 minutes skip boots and go right for it, other wise get boots then go to blade mail.
Mid- Blade mail is hands down the best item on Bloodseeker and is honestly the one item that makes him increasingly viable. Upon completion you will be able to kill just about anyone 1v1, or even 2v1 if you're lucky. Armlet following power treads and blademail will give everything you need. Also Armlet will allow you to deny yourself every time.
Late - BkB will allow you to chain BKB to Blademail to maximize damage return effectiveness
Some replays for insight behind the build.
Rupture and blade mail will force your opponents hand. They will either run, cast on you if you haven't silenced them, or auto attack you assuming they are silenced. Either way, any decision they make is bad news bears and will score you a kill.
Blade mail damage can Proc blood bath and will heal you.
It also can be very beneficial to oncoming ganks, if you can get blade mail off before the gankers release their damage on you you'll most likely be able to reflect a good deal of damage. On top of a rupture you will be able to bring them to 44% or lower hopefully and you can just run away with max move speed from your Thirst passive. There are too many scenarios this item will provide that are beneficial to you. Basically winning the dps race against opposing heroes and healing off of Blood bath.
Also if you have Dark seer as much as I do, pick this hero to counter him :)
Armlet - This will allow you to deny the enemy team of ever killing you. Simply Bloodrage yourself and de-toggle the armlet and you will kill yourself before the opponent can. A broken mechanic I've known about but now have decided to let out ^_^