12 Jul 2019
If a card in your graveyard has {X} in its mana cost, X is considered to be 0 while you target it with Chandra’s last ability; however, once you begin to cast it, you choose a value for X. If this causes the mana value to become greater than 3, you can still cast the spell.
12 Jul 2019
If you wish to cast the target card, you must cast it while Chandra’s last ability is resolving. You can’t cast it later in the turn.
12 Jul 2019
You must pay the costs for the spell you wish to cast with Chandra’s last ability. If that spell has any alternative costs, you may pay those.
12 Jul 2019
Chandra’s first ability will put a counter on herself as well as any other red planeswalkers you control. This doesn’t cause any other planeswalkers’ loyalty abilities to be activated.