Complex sentence: Formerly the interrogator (an inquisitor-in-training) of the infamous Gregor Eisenhorn, Ravenor's career in the Ordos seemed promising until he was critically injured during an event that became known as the "Thracian Atrocity" on Thracian Primus.
Split into simpler sentences: Formerly the interrogator (an inquisitor-in-training) of the infamous Gregor Eisenhorn, Ravenor's career in the Ordos seemed to be a promising one. Tragically, he was critically injured during an event that became known as the "Thracian Atrocity" on Thracian Primus.