Given that Mega Evolution is expected to mainly contain cards from Japan's Mega Symphonia and Mega Brave sets, it seems almost all of these Mega exs have now been confirmed in one form or another
But once they catch up, the market will flood for a while
The deck focuses primarily on using self-mill effects and rad counters, combined with The Wise Mothman's effect, to quickly pump your creatures making them massive, so that you can easily overwhelm your opponents
They were all brought over, although their stay would be just for Fourth Edition, where they would be lost in time afterwards
(They create a Clue token.) II, IV Create a 2/2 black Alien Angel artifact creature token with first strike, vigilance, and "Whenever an opponent casts a creature spell, this permanent isn't a creature until end of turn." People often assume that Sagas are a strict progression from top to bottom, but actually, from a non-linear, non-subjective viewpoint, it's more like a big ball of wibbly wobbly, timey-wimey