It can do a lot of neat things. For those of us who throw 2-3 multi-color site in our deck in case we face site lockout, but end up NOT facing site lockout, we can use it to turn our otherwise worthless rainbow site into a defensive card (single color site). It can also give us access to lost souls we could not reach, while simultaneously getting rid of annoying fortresses like Satan's Seat that require a single color site.
And then of course on defense it is another way to mess with an opponent's multi-color site.
