Q1: Which player chooses 1 of each player's Digimon with the highest play cost for this card’s effect?
The player that uses this card chooses.
Gaia Reactor EX4-069 U [Main] Choose 1 of each player's Digimon with the highest play cost. Delete all other Digimon. --- [Security] Activate this card's [Main] effect.
Gaia Reactor EX4-069 U [Main] Choose 1 of each player's Digimon with the highest play cost. Delete all other Digimon. --- [Security] Activate this card's [Main] effect.
Gaia Reactor EX4-069 U [Main] Choose 1 of each player's Digimon with the highest play cost. Delete all other Digimon. ---
ガイアリアクター EX4-069 U 【メイン】最も登場コストの高いお互いのデジモン1体ずつを選ぶ。選ばなかったデジモン全てを消滅させる。 --- 【セキュリティ】このカードの【メイン】効果を発揮する。