Just ran the Arborback Stomper node in Fateful Showdown and failed the Protector objectives with 6 creatures lost. Only, I was running flying creatures and none of them were removed from the field. Unfortunately, one of those creatures was Mindwrack Demon ( I’m mastering cards 
) and so I ran the node again and discovered that creatures being discarded from my hand when Mindwrack Demon entered the field counted as lost creatures.
/Edited title - Daiane
Hi @Brakkis,
Thank you for report this!
We’ll check.
Just a heads up, this is effecting Hour of Devastation and triggering Embalm gems on the field counts as losing a creature.
Oh yeah. This sucks. I’m hucking Hydras into the gy en masse and getting penalized for it. 
Just wanted to add that I believe Charnel Troll has the same effect. (not positive, but I was also mastering and had a fairly vanilla 10 creature deck with no other apparent causes.)
It was a replayable event (OGW II), but I still wasn’t too happy when I saw this after the match…