Strygwyr the Bloodseeker is a ritually sanctioned hunter, Hound of the Flayed Twins, sent down from the mist-shrouded peaks of Xhacatocatl in search of blood. The Flayed Ones require oceanic amounts of blood to keep them sated and placated, and would soon drain their mountain empire of its populace if the priests of the high plateaus did not appease them. Strygwyr therefore goes out in search of carnage. The vital energy of any blood he lets, flows immediately to the Twins through the sacred markings on his weapons and armor. Over the years, he has come to embody the energy of a vicious hound; in battle he is savage as a jackal. Beneath the Mask of the Bloodseeker, in the rush of bloody quenching, it is said that you can sometime see the features of the Flayers taking direct possession of their Hound.
For abilities, stats, and other information, visit this hero's Liquipedia page here: http://wiki.teamliquid.net/dota2/Bloodseeker