Energy Shield附属在敌人上时，显然在场上。
OWNERSHIP AND CONTROL规则中的第二点，Cards enter play under their owner’s control. Encounter cards are considered to be under the control of the scenario.这条规则指出了在场的牌由其拥有者控制。
遭遇不由任何玩家控制，后面的补充第一小点Upgrades attached to a card controlled by a player other than the upgrade’s owner are controlled by that other player.这条规则针对的是升级附属在其他玩家控制的牌上，与Energy Shield附属在敌人上的情况无关。