At its simplest, this is a card that gives you
two 2/2 tokens at instant speed. That's already
decent, but it's far more than just a one-note
deck space filler. With all the mana production
in green, you should not only have no problem
paying for most creatures you manifest a second
time, but you may be effectively using this card
to get things into play earlier than you should.
Even if that ends up not being appealing with
recent creatures, let me remind you of two words
that have echoed down Magic players' minds since
1996: Phyrexian Dreadnought.
Today's card of the day is Ethereal Ambush
which is a five mana Green and Blue instant
which has you manifest the top two cards of your
library. Five mana to put two 2/2 into
play at instant speed is fairly powerful and the
potential to turn them over does give some
additional value. Overall this is a little
too expensive and in the offbeat Blue/Green
combination to see competitive play, but it
could be seen in Casual or Commander decks
In Limited this is noticeably stronger as it
puts two creatures into play at instant speed
and in the creature dominated format the
Manifested cards are very likely to be
creatures. As a common it can be used in
multiples in Sealed if running Green/Blue to
help fill the field up and it is worth splashing
in if the deck needs a little something extra.
In Booster this is a strong middle of the pack
pick if primarily in one of the colors and is an
early pick if already committed to both Green
Manifest is a tricky ability. Just getting two
2/2's for 5 mana is not a particularly great
investment. But sometimes, either by luck or
some shrewd library manipulation, either or both
of those 2/2's can potentially flip up and
become something much scarier.
Some people are really concerned when they
manifest a non-creature card that they wanted to
draw, and now consider it lost forever. Remember
that there are many "return target creature to
owner's hand" cards and effect that can bounce
such a manifest to your hand at instant speed.
If the manifested card is an instant, you could
also play it!
I think there's some potential for manifest, but
in this case, it's too high a cost.