allows you to add any Subterror card from your Deck to your hand when he's flipped face-up
When I suggest the possibility of, say, a quad-faced card (a physical impossibility in the real world), Forsythe says that actually sounds "totally reasonable" as skirting around physical limitations is exactly the kind of thing digital card games should be trying to do. Forsythe jokingly provides his own example of a crazy effect that would actually be going too far playing a game of Space Invaders to determine a creatures toughness when it enters the battlefield
It's a -1 in card economy, unlike Dragged Down into the Grave, but it doesn't allow the opponent to potentially draw another hand trap
This card is a soft once-per-turn, meaning that if players controlled multiple copies of Zoodiac Drident, they could use the effect multiple times in a turn
Skithiryx allows for very aggressive decks that tend to utilize either infect-focused strategies or Voltron strategies that bolster the effectiveness of Skithiryx itself
While its valuable to recognize these edge cases, sticking to 60 cards is typically the optimal choice in Standard and other Constructed formats