He lives in and operates a museum inside his home. His home features a number of Mythic Dawn artifacts in locked display cases. These include all four tomes of the Mythic Dawn Commentaries and a tattered page from the Mysterium Xarxes. One display case also contains a full set of Mythic Dawn apparel, robes with and without hoods, gloves and shoes, which he also wears. The robes bestow a 75% faster Magicka Regen effect upon the wearer.
If the Dragonborn kills Silus inside his museum and steals the artifacts inside, they may be attacked by hired thugs carrying a contract from Silus.
If Silus dies after telling him to run away at Mehrunes' shrine, a courier may show up with an inheritance of 90 gold and a letter from Jarl Skald the Elder (or Brina Merilis if the Imperials have taken over the Pale) informing the Dragonborn of Silus' death.
Like several other NPCs his body does not disappear