Lucario ex Aura Sphere questions

I’ve got a couple questions about how to resolve the Aura Sphere ability on the Scarlet & Violet Lucario ex card. First, who chooses which benched Pokemon takes the 50 damage, the Lucario player or the opponent? Second, when does the 50 damage happen in relation to the active Pokemon getting knocked out? Specifically, if the active Pokemon is knocked out by Aura Sphere, does a benched Pokemon immediately take its place as active, and so cannot be targeted by the 50 damage, or does damage to both active and benched Pokemon happen simultaneously, so a benched Pokemon can get hit even if it will become the new active? Thanks for any help! submitted by /u/Cpl_Toast [link] [comments]