From Guild Wars Wiki
Location in Perdition Rock
- This boss can appear in any of the five possible spawn locations, which he shares with seven other Abomination and Phantom bosses. Keep in mind that there can be up to two bosses at each spawn location.
- Does not always spawn.
- The name means "Wicked Haunt" in Latin. Another possible meaning for Pravus is "Evil" and "Depraved"; while Obsideo can mean "To Besiege".