Brigid, Clachan's Heart

A nonmodal double-faced card enters with its front face up by default, unless a spell or ability instructs you to put it onto the battlefield transformed or allows you to cast it transformed, in which case it enters with its back face up.

Each face of a nonmodal double-faced card has its own set of characteristics: name, types, subtypes, abilities, and so on. While a double-faced permanent is on the battlefield, consider only the characteristics of the face that's currently up. The other set of characteristics is ignored.

In the Commander variant, a double-faced card's color identity is determined by the mana costs and mana symbols in the rules text of both faces combined. If either face has a color indicator or basic land type, those are also considered. For example, Oko, Lorwyn Liege's color identity is green and blue, since its front face is blue, its rules text contains a green mana symbol, and its back face has a green color indicator as well as a blue mana symbol in its rules text.

The first ability of Brigid, Doun's Mind is a mana ability. It doesn't use the stack and can't be responded to.

Each nonmodal double-faced card in this release is cast face up. In every zone other than the battlefield, consider only the characteristics of its front face. If it is on the battlefield, consider only the characteristics of the face that's up; the other face's characteristics are ignored.

If you are instructed to put a card that isn't a double-faced card onto the battlefield transformed, it will not enter at all.

The back face of a nonmodal double-faced card usually has a color indicator that defines its color.

In some rare cases, this permanent might transform while its triggered ability that allows you to pay mana to transform it is still on the stack. (For example, another effect might cause that ability to trigger an additional time.) In such a case, even if you pay mana as the triggered ability resolves, this permanent won't transform because it already transformed while the triggered ability was on the stack.

The mana value of a nonmodal double-faced card is the mana value of its front face, no matter which face is up.

A token that is created as a copy of a double-faced permanent or a double-faced card in another zone is a double-faced token. It will have both the front face and back face of whatever object it's copying. If it's copying a double-faced permanent whose back face is up, the token will enter with its back face up. It can transform if instructed to do so.