I wish I took more details, but
Mind's Desire acts really strange, sometimes letting you repeatedly cast the same sorcery or instant (after
Mind's Desire resolves, click the "Flashback cards" section, cast one of the exiled cards, then sometimes it'll move to the top of the "Flashback" pile as opposed to the graveyard). Also, I once cast
Jace, the Mind Sculptor, and even though it's a permanent, it still was trippy: in addition to the loyalty abilities, I could choose "You may cast Jace without paying its mana cost".
Also, when playing against Superman, the "counter placed" sound plays most of the time either player passes priority for no apparent reason. I watched closely and nothing such as suspending a card (which can normally be easy to miss) happened, so no idea what went on there.
EDIT: Also, Jace can perfectly unsummon the opponent's creatures even they have
Kira, Great Glass-Spinner in play; the ability will trigger and seem like it'll counter Jace's ability but not actually do so.