Archangel Avacyn can’t be killed with Improsoned in the Moon in its 1st round. I tried twice and failed but the “moon” token was created…It showed a red -0 we I targeted the Angel in its 1st (come into play) round…After the prevent Damage wore off, the “moon” worked. From my understanding “Moon” Destroys a creature not via direct damage
Prevent Damage is bugged; see Prevent Damage Causes Immunity To Kill Spells [Fixed in 2.1.2] - MtGPQ Bugs & Technical Issues - 505 Go! Official Forums
Thanks for your reply