Yang ‘Sen’ Chia Cheng is a Zerg player and former Brood War player from Taiwan, currently playing for Hong Kong Attitude.
Sen has been one of the few Zergs to have consistently strong ZvT, even during the periods of Terran dominance. Sen can play almost any way he wants, as he seems equally comfortable with any tech, timing attacks (particularly in ZvZ), and harass-based play. However, he is probably most renowned in the foreigner community for his overwhelming macro. A long time practice partner of theirs, both Day and Tasteless speak very highly of Sen, who seems to always have more stuff than his opponents can manage to produce.
Perhaps more so than any other foreign Zerg, Sen is the complete package and a difficult player to predict.