When you first zone into Bloody Kithicor you’ll see two NPC’s. Speak to each of them to get a “faction” necklace from each.
Scout Talendien – Say “will” to receive Army of Light Pendant
Scout Zialdiruun – Say “need” to receive Army of Obliteration Medallion

Each of these necklaces will grant +1000 faction to one of the two factions within the zone, and -100 to the opposite. You’ll need both Necklaces as you’ll be doing quests in for each faction.

Once you have each necklace you can begin Bloody Kithicor progression.