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.
2019-07-12 • wotc
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.
2019-07-12 • wotc
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.
2019-07-12 • wotc
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.
2019-07-12 • wotc