
Bloodseeker is a melee agility carry and ganker, with potentially fantastic mobility and the ability to lockdown or chase enemy heroes. Although never picked competitively, he can dictate the pace of a public game with a couple of successful ganks under his belt.
Skills
Put your first point in Bloodragw and max it first or second.
Thirst helps make you a scary ganker, max it right after (or before if you prefer, for all-out ganking) Blood Bath.
Get an early point in Blood Rite but max it last.
Always get Rupture when you can (levels 6, 11 and 16). Gank or kill your lane opponent as soon as you hit level 6.
Items
Starting Items - Stout Shield, Quelling Blade and either a set of Tangos or a Healing Salve.
Core - Poor Man's Shield, Magic Wand, Power Treads.
Then:
Farming Well - Radiance.
Farming Poorly - Yasha or Force Staff.
Attack Speed Build - Maelstrom into Mjollnir.
Luxury Late - Butterfly, Monkey King Bar, Daedalus, Heart of Tarrasque.
Utility Items - Black King Bar, Assault Cuirass, Vladmir's Offering, Abyssal Blade.