What changed with the hidden rules in the October 23rd patch, specifically regarding hidden cards and battlefield control?

Ruling: The October 23rd patch provided clarifications rather than new rules. The main change allows you to hold your hidden card until after damage calculation before revealing it.

Sequence:

• Damage calculation occurs
• You can then choose to reveal your hidden card
• This timing allows you to avoid unwanted triggers or protect units from being killed

Nuances:

• This can be used with cards like Hourglass to avoid it triggering on undesired targets
• The interaction with Shen (unflipping after damage calc to avoid death and maintain battlefield defense) was mentioned but remained unclear to the discussants