Reasoning — Ruling

Effetto 0

If there are no monsters that can be Normal Summoned in your Deck, you cannot activate Reasoning.
If you excavate a monster that cannot be Special Summoned, such as "Tsukuyomi", it is not Special Summoned, and you send it to the Graveyard alongside the remaining cards.
Declaring a level and excavating cards happen during the effect's resolution.
Reasoning does not target any monsters.
Special Summoning the monster and sending the remaining cards to the Graveyard happens simultaneously.