Let Her Go First

You're on 7 and B is already scored. Leona holds A with an Adaptatron (3) and a Stellacorn Herder (3); your Magma Wurm (8) beats them 8 to 6, and you hold Hextech Ray (Action[Action]: deal 3 to a unit at a battlefield). She kept two Calm runes ready with one card in hand, and she played Discipline (Reaction[Reaction], 2 Energy: +2 Might this turn) earlier this game. Take A: who should play first?

• Move: drag ready units onto a battlefield (or click units, then click where they go). They wait there, faded, until you press Confirm in the panel on the right — units that fight together must move together.
• Runes: playing a card pays from them on its own. To float Energy or Power first, click a rune: Tap gives Energy, Recycle gives Power.
• Cards: drag a card from your hand onto its target, or click it and then click the glowing target. The play waits in the panel on the right until you confirm it (Esc cancels).
• Abilities:click your Legend (one click uses its ability), Gear, or a unit's ✧ badge.
• Point at any card to see it large; right-click to read it. Hint, Undo and Retry are at the top.