Presuming a typical "high[ish] fantasy, magical world, devoid of real world religious mythoi, I say you make the mythic figures your own.
Turn it on its head. They are arriving (according to some prophecy or the other), from no one -not even the deities- knows where, and they are going to "destroy the world." But what people don't immediately know/understand is, they are looking to destroy the world...that exists. They are coming to "conquer." To take charge. To reorder this chaotic and violent world under their nigh unstoppable thumbs (and, perhaps in the case of one or two, heels). They aren't "death, pestilence, war, famine" but those all may [or will] certainly erupt in their wake.
Four entities, mounted upon diverse creatures (a draconic-breath weapon and all-wyvern, a pegasus with billowing stormclouds as mane and tail, giant griffon-with blue striped tiger body, and snow-leopard/silver dragon version of a dragonne, come to mind, off the top of my head). They are shining, celestial-seeming, in their beauty and the obvious power/otherworldly nature of their vestments/armor, weapons and gear. Two male, two female. Armed with an assortment of weapons and all, obviously, with magical abilities.
For me, this sounds like a "start" of a campaign, not an ending.