Because you consider only the characteristics of a double-faced card's front face while it's not on the battlefield, the types of its back face won't be counted for delirium
However, if you do choose a target, and that target is illegal at the time Rat Out tries to resolve, the spell won't resolve and none of its effects will happen
Consecrated Sphinx This creature rapidly spirals out of control and it can be difficult to answer it if youre not prepared, because the card advantage that it provides its controller will rapidly outpace the rest of the table and likely keep them stocked up on counterspells and other protection to keep this engine going until theyre able to win the game
For the same purpose, the deck also runs copies of [c]Serras Sanctum[/c]
Summon: Primal Garuda gives a little bit of spot removal along with 2 turns of flying for Steiner
This card is super playable there