New Legend Rule + Night of Souls Betrayal

[Phoenix Ignition]

If there are some 2/2 creatures in play and I have a Night of Souls' Betrayal out (effectively making them 1/1s) do they all die when I play a second NoSB? From what I understand there is some amount of time where both are in play and I am making a decision as to which of my Legends to keep, at which point I think all of the originally 2/2 creatures turn into 0/0s and die. Is this correct or do they stay 1/1s for the entire process?

I've had differing answers from differing judges, and it may have changed due to the new legend rulings.

[Tormod]

Great question

[whienot]

704.3. Whenever a player would get priority (see rule 116, "Timing and Priority"), the game checks for any of the listed conditions for state-based actions, then performs all applicable state-based actions simultaneously as a single event.

704.5. The state-based actions are as follows:

704.5f If a creature has toughness 0 or less, it's put into its owner's graveyard. Regeneration can't replace this event.

704.5k If a player controls two or more legendary permanents with the same name, that player chooses one of them, and the rest are put into their owners' graveyards. This is called the "legend rule."

In your scenario, the base stat 2/2s will become 0/0s and die and you will sacrifice one of the legends all as one action.