Chandra, Pyromaster

In the third ability, "exiled this way" means the cards you just exiled because of that ability resolving. Cards exiled with the second ability or with previous activations of the third ability don't count.

If the first ability resolves but the damage is prevented or redirected, the target creature still won't be able to block that turn.

The card exiled by the second ability is exiled face up. Playing it follows the normal rules for playing that card. You must pay its costs, and you must follow all applicable timing rules. For example, if it's a creature card, you can cast it only during your main phase while the stack is empty.

If the copied card has {X} in its mana cost, you must choose 0 as its value when casting the copies.

While casting the copies created by the third ability, timing restrictions based on the card's type (such as creature or sorcery) are ignored. Other restrictions, such as "Cast [this spell] only during combat," are not.