The random loot mechanic for obtaining Sigils in Necropolis 4 is upsetting and an obtuse time-sink within the game. So far, I've enjoyed that DDO hasen't required any mandatory grinding for plot advancement; until I ran this quest series. While grinding for gear/experience is acceptable, I find the requirement to obtain 7 random end-chest plot items to be excessive and take away from the gaming experience in DDO. Grinding should be used to reward players who want to put in the extra effort to enhance their characters, not to be punitively used to hinder deserved progression. In addition, this is not a F2P adventure pack making this time-sink grinding mechanism an ethical dilemma: it's not ethical to have some players move plot through luck and especially egregious in consideration for customers on time-based subscriptions.
I implore you to address this issue in a future update for these types of quests as I speak for many customers who also feel equally upset about the implementation of using arduous end-chest random loot grinding to advance main quest plots.