xienwolf
Deity
Actually, instead of a ritual I might make it a process. Then he is lured to your city only for as long as the city is acting to lure him, but the city doesn't REQUIRE any production at all to accomplish it (though it also cannot swap over to make backup defenders while you wait for arrival), and you can break off the attraction at will. I can potentially make this a seperate process per Horseman, so that you can choose which to lure if 2 are in the world at once, and don't summon down quad-doom on yourself should all 4 be in the world at once.