In the Mortuary Edit
Telling Soego about Vaxis rewards 250 XP.
Telling Soego that TNO is lost will prompt him to call the guards, but he can be subsequently dissuaded from it with 11 Charisma.
TNO also has the option of snapping his neck (requires 13 Dexterity). This option never kills him however, and results in combat.
If killed or pick-pocketed, the following items can be found on Soego's person:
After TNO leaves the Mortuary, Soego disappears (if he wasn't killed), supposedly on a self-imposed mission for the Dustmen. Emoric has a quest to find out where Soego has gone, should TNO ask him to join the faction.
Sere the Skeptic says he was shaken up after one of his friends was attacked and torn to pieces by rats in the Hive.
Dead Nations Edit
After TNO and his party are captured by the undead in the Dead Nations, he is taken to a small chamber where Soego is also kept. Here, TNO can rest. Soego explains that he is a missionary here because the undead here are moved by passions that prevent their attaining the True Death.
Soego can be told of the Doubtful Skeleton nearby, and he will immediately leave to find his new convert. With his possessions now unprotected, TNO can examine the Metal Slab he's been sleeping on, and find his journal (rewards 2000 XP). This journal reveals Soego's true nature: a Wererat, and that he came to the Dead Nations to spy on them for Many-as-One, who hopes to gain some of the Dead Nations' territory.
When confronted about his nature, Soego immediately turns into a rat and attacks. Killing him grants some coppers and Soego's Skull, which will be useful later.