You can control two of this permanent, one front-face up and the other back-face up, at the same time.
Chandra, Fire of Kaladesh // Chandra, Roaring Flame
The back face of a double-faced card doesn't have a mana cost. A double-faced permanent with its back face up has a mana value equal to the mana value of its front face. Each back face has a color indicator that defines its color.
If a double-faced card is manifested, it will be put onto the battlefield face down (this is also true if it's put onto the battlefield face down some other way). Note that "face down" is not synonymous with "with its back face up." A manifested double-faced card is a 2/2 creature with no name, mana cost, creature types, or abilities. While face down, it can't transform. If the front face of a manifested double-faced card is a creature card, you can turn it face up by paying its mana cost. If you do, its front face will be up. A double-faced card on the battlefield can't be turned face down.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Eric Deschamps
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
