A wolf and a penguin could never live together, nor could a camel and a hippopotamus. That would be absurd.
And the older you get, the fewer things you really love. And by the time you get to my age, maybe it's only one or two things. With me, I think it's one.
I assume, you have to pay becoming emperor or caliph with one of your cubes, like every other special action?
I wonder, because it's so ineffective then. The cube you put onto the emperor/caliph special action, you could alternatively use for an increase army action, and this cube would stay on the elite space of your army table.
Sure, you do not have to maintain the emperor/caliph cube, but it disappears at the and of the round, which "costs" effectively the same, as paying one elite cube staying for one more round.
Yes, you must pay a cube. Remember to score 2VP for these actions.