MDFCs are good, yall
(When a creature with afterlife 1 dies, create a 1/1 white and black Spirit creature token with flying.) Because blockers are chosen all at once, you can't block with a creature with afterlife, wait for it to die, then block with the resulting Spirit tokens
Additionally, the benefits you gain are hardly worth the effort of having them in play
Julieta herself is a great target for Rapunzel's ability thanks to her four Willpower, so if you can challenge something with Julieta on turn four (using Mirabel's support again) you can immediately heal her with Rapunzel and draw even more cards
Indeed, these win cons may seem easy to overlook, but if played correctly, they can take your opponents by surprise and win you games in ways you previously would have otherwise written off
You may cast it and never level it up, or you may wind up grinding it all the way to to level 3 over the course of the game