You can pat yourself on the back for clever use of the legend rule to be your sacrifice outlet, and yes you come out with a measly one treasure per transaction, a lot of other triggers happened along the way, when a creature dies, when an artifact comes into play or is sacrificed, those payoffs can win you the game
At worst, this is a 5 mana, draw multiple cards spell, essentially, assuming you immediately kill it for its -3 ability
Leyline can be hit or miss against these types of decks
They were a great foundation for what would become one of the best Final Fantasy enemies
Over the years, Wizards has toyed with many different flavors of Sagas--variable number of chapters, all kinds of effects, creatures that transform into Sagas, Sagas that transform into creatures (especially in Kamigawa: Neon Dynasty) , and even an Enchantment Land that's also a Saga
In fact, I think this card is kinda nuts