Quoigulla, the Traverser

Instead of paying either red or white mana
pay orange (orange = red and white at the same time)
{r/w}{t} Prism 4 ( Prism: when activated, player can choose one card to
be exiled and placed under this card face up.
This process can be repeated X times where X is the strength of the prism
[i.e. prism 4 is up to four cards stored])