In your world, a world you don't know/remember, it was frozen over. Everything and everyone were frozen in a massive block of ice that covered the earth... everyone and thing had frozen to death... But you, an egg, a large one at that (about the size of an indoor trashcan), just sat dormant in the ice, in your egg.. waiting for the right temperatures do you could incubate and hatch... One day however, something happened... and an interdimensional vortex opened and sucked you (still an egg) in!

Emperor Raiden was just... minding his business in his castle (more of a Chinese style castle), in his completely non-supernatural world when suddenly, he heard a weird "viiirr" noise and a small "thud" in the soft grass of his garden. Confused, he got up and went to investigate. When he got outside, he saw.. an egg (you) incased a block of ice. (Emperor Raiden doesn't know about anything mythological cause in his world supernatural things don't exist)

Emperor Raiden: "Huh? What in the lord's name is that?" He asked as he walked over to you (the egg)