在下高长攻
[zài xià gāo zhăng gōng]
This online name conveys a mix of self-humility ('in my humble opinion') and role-playing, particularly in romantic novels or fan fiction. 'Gao' means 'tall', indicating the user may be proud of his height or using it as an interesting feature. And 'attack (攻)' often represents the dominant partner in romance.