Complex sentence: This was in fact the former Chinese first-person "singular" pronoun (i.e., "I") but following his unification of China the emperor Shi Huangdi arrogated it entirely for his personal use.
Split into simpler sentences: This was in fact the former Chinese first-person pronoun (that is,'I'). However, following his unification of China, the emperor Shi Huangdi arrogated it entirely for his personal use.