Keine, Concealer of History

While casting this spell, you may remove lore
counters from among Sagas you control, each
counter you remove pays for {1}.
Whenever you sacrifice a Saga, you may exile it.
If you do, search your library for a Saga card
with lesser mana value and put it into your hand,
then shuffle.
{r}{g}: If you own three or more Saga cards in
exile, transform Keine.