this name is going to give a lot of confusing, you have a FG called rainbow, a deck-type called Rainbow and now a card called rainbow. Rainbow uses a rainbow deck which is based around rainbow. ???
Now we need to find a fitting song by Rainbow, or maybe fight Rainbow with a mono-dark while this (
&feature=related) play on the background. XD
nah, just kidding.
This card is really nice, and will help with many Rainbow decks. Having counters helps with it's OP'ness, as well as the reasonable cost.
The only problem being, Other cards are mostly really basic (Shield, for example), the ONLY difference being the pillar. It ain't bad, and i don't think it will fit any other element, but just a thought.