Thanks for the feedback!
Yes, we could definitely add in a <Discard Random X> as a card action. Adding from the Enemy’s side is a little more complicated (given that they currently don’t have their own decks), but it should be possible to setup where them succeeding on an attack can proc a separate skill which makes the target have to discard.
As for Discarding from top of deck (Milling type actions/costs), that will be included in the next major update as part of the Card Filtering feature (Version 1.4.0).