Secrets and collectibles/Unique orcs

So far only Orcent and the dead Zirantian orc are not optional.
 * Orcent - Unavoidable.
 * Stark - Found in the shrine on the second visit to the Feroholm region.
 * The Impaler - Unavoidable, but the player can choose to kill or spare him.
 * Ralke - Requires failure of the Orc Extermination proposal.
 * Implevon the Third - Requires raising Orc Intelligence to 10 or higher with Balia.
 * Dead Zirantian orc - Unavoidable loot from a tomb in Zirantia.