Dictate of Erebos and Bestowed creatures
You may sacrifice Underworld Coinsmith, and then you may sacrifice Hopeful Eidolon.

Whenever a creature dies, all of its enchantment(s) become unattached. Normally, they would be sent straight to the graveyard as a state based action. However, enchantments with Bestow immediately become a creature instead due to rule CR 702.102a. The commonly used slang terminology for this action is "falls off".

Triggers from Dictate of Erebos resolve one at a time. If you sacrifice Underworld Coinsmith to the first trigger, then Hopeful Eidolon immediately "falls off" and is ready to be sacrificed to the second trigger.


  702.102a If you chose to pay this spell’s bestow cost, it becomes an Aura enchantment and gains enchant creature. These effects last until the permanent this spell becomes becomes unattached.