Welll, we already have white/red/black in terms of the samurai colors, and white/red and white/black are enemy colors. Also black and green, enemy colors, seem to have the strongest selection of spirit type creatures. Maybe some enemy color alliance is not entirely impossible, although from a flavor standpoint it would seem to me to make more since in Saviors, with enemy colors "coming together" to save the world blah blah hackneyed storyline.
not a super powerful combo, but what with the healer being a common, it shouldn't be too terribly rare of a pull.
That seems good enough to be useable both as a free card or with the mana cost, without being overpowered.
w00t first post.