I played Malorne the Waywatcher and the 3 cards didn’t show up. When I tried to click anything, my hero just said “I can’t do this.” It was as if the discover interface was open and hidden. Except it wasn’t.
Also in a different discover effect, Zilliax Deluxe 3000 showed up.
Zilli begging people to play him. The fall from the grace hit him hard. 
Why is that a bug?
20chars
Zilliax is excluded from discover effects. You can’t choose modules, when discovering him. He had no mana cost and no stats. I don’t even know what would’ve happened if I actually picked and played him.