They gain control of this artifact
While there are many directions that we could have focused on with him, the two most important ones were the Malus Codicium , a grimoire of devastating potential, and Cherubael, a daemonhost whose destiny is intermixed with Eisenhorn and who he eventually controls with the aforementioned book
Additionally, if you have attacked with two or more creatures this turn, you can pay one generic and one white mana, tap Minas Tirith, and draw a card
However you can sacrifice enchantments for interesting things, also interesting with the Seals - Seal of Doom for example, though Sagas are officially sacrificed when they hit the final lore counter, so this is some really strong Saga synergy
I got such a rush when I read the assignment, especially since the working title was Force of I almost couldnt believe it