Easy solution for the Mordor cluster nerf. You can add them for the price they have in BBs merits:

90 Motes for 1 empowerment scroll
300 Motes for 1 crystal

Although I think it should be reduced (both Motes and Merits), maybe to this:
50 Motes for 1 empowerment scroll (90 is just too much if you compare with the CoS drops - having in mind you get 300 Motes for 1 Mordor dailies day, it would be 6 empowerments if 50 Motes each, comparable to a lucky day at CoS or even the Minas Tirith dailies)
200 Motes for 1 crystal (you don't need as many as empowerments but it's still a huge grind)

This way you don't only make running Mordor cluster useful, but also you make useful to do Metadeeds and to continue running the Mordor dailies
And also, seriously, why is the reward for a metadeed that can take a few days the same than Mordor dailies that can be done in less than 1 hour? - this is for another topic but metadeed reward should be at least 1000 Motes