The Ancient Vampires worshipped and communicated with the Elder God, the war with the Hylden was basically feeding Elder God with souls that are killed in the war, the Ancient Vampires erected the Pillars to banish the Hylden into the Demon Realm but in revenge they infected the Ancient Vampires with immortality which caused the Elder God to be deprived of souls to feed upon which made him go silent on the Ancient Vampires. But why didn’t the Elder God order them not to erect the Pillars in the first place since they worship him and would have followed his commandments? or was it because the Ancient Vampires planned and created the Pillars without the Elder God’s knowledge?, but considering the Elder God most probably watched the Ancient Vampires in their every move, could they have planned all of this in secret from him?