I've avoided double faced cards up to this point. The biggest reason is just the complete hidden information during the draft. They're also often very complex and the logistics of flipping cards around isn't great. There are plenty of cards, excluding this small set doesn't take much away.

Twinblade Geist has made me break that rule though. Double strike is a great mechanic that interacts with a lot of other effects. Fencing Ace is just a bit under-powered for this context. Adorned Pouncer has been in the list for a long time and it's doesn't play great. Players aren't especially excited about it and then when you can eternalize it, it's a must-answer threat that takes over the game. Twinblade Geist is a Fencing Ace with upside that's much more appealing. The second half is less punishing, more castable, and has even more potential to combine in novel ways with other cards. Of the double faced card mechanics, disturb is definitely my favorite and at the cost of some hidden information, is the cleanest implementation of 'flashback for creatures'. If I hear enough people asking what this card does on the back I may cut it, but for now I'm giving it a try.

By Invitation Only is a very interesting card. Wraths have played in a bit of a weird way in this environment (or not been played at all). As a modal wrath that may make a lot of sense in decks that are otherwise still largely focused on creatures I think it's much more powerful here than other options at 5 mana. It may be that this card is way over-powered and is an auto play in all decks that can cast it so I'm skeptical it'll last, but I think it's worth a try.

I meant to include Portable Hole earlier and just missed it. I'm always happy to have more interaction at an appropriate power level.

I'm not necessarily trying to make 1-for-1 swaps, but my white section is a bit heavy. (I feel like the only cube designer with this problem.) Giant Killer is a fine card, but has played out a bit awkwardly. The spell has surprisingly few targets, but it still feels like you're doing it wrong if you cast the creature early.