I really like Manifest as well, but I think we need to choose either Manifest or Kamigawa-Flipping, or we get confusion between the two types of flipping over. Personally, I like the kamigawa-flipping just because with a Dream sub/super type, it is a very obvious representation of dreams while still allowing variety between things, instead of always 2/2s. Still, if a lot of the cards were to be enchantments like Rageform, that could be cool, but I think many of them would need to say "Enchant Manifested Creature" to balance it when it flips and allow more cost-effective dream creatures. And even if that did work out, we just had a set with lots of Manifest
The way I was using it, the original object/creature is generally "real", and flipping it makes it a "dream". This is further represented both by becoming a new type (enchantment) and gaining the Dream super/sub type (still not decided on what Dream would be).
In my two examples earlier, they were both creature -> enchantment, but you could do the other way around or something different as well. For example:
Sophia's Presence 1WW
Enchantment - R
At the beginning of each turn, gain 2 life.
When you have 10 or more life more than your starting total, transform ~.
In the Material, she is a comfort.
Sophia, Dreamweaver Angel
Creature - Angel Dream R
Flying, Lifelink, Vigilance
~ can only be blocked by Dreams, and only takes combat damage from Dreams.
When dreaming, she is a savior.
3/7