MTGNexus

Yennett, Cryptic Sovereign and Necrologia

You may see where this is going.

Obviously Yennett, Cryptic Sovereign allows you to cast creatures, sorceries, etc outside of their normal timing restrictions, but Necrologia very specifically states that it can only be cast during the end step.

Which takes precedence? Does the timing limitation on Necrologia count as a "negative" for rule 101.2 and thus can't be cast even with Yennett, Cryptic Sovereign's triggered ability? Or does 101.3 apply and the cast timing restriction on Necrologia is "impossible to perform"?

Generally speaking, the game is built upon the idea that things are "permissive" not restrictive. That is, you can cast creatures during your main phase when the stack is empty because that is the only permission you have to do so. Yennet adds to those permissions to give you another window in which to cast spells.

However, the text on Necrologia is a restriction and, in Magic, "can't" always beats "can" so that one restriction is enough to prevent you from using any of your available permissions.

So, no, you cannot cast Necrologia off Yennet because Necrologia says you can't.

Comprehensive Rules wrote: 101.1. Whenever a card's text directly contradicts these rules, the card takes precedence. The card overrides only the rule that applies to that specific situation. The only exception is that a player can concede the game at any time (see rule 104.3a).

101.2 applies, but I believe 101.1 is more relevant here - Necrologia can only be cast during the end of turn step, so it can't be cast during combat.