Can Shen be played in response to a Deathknell trigger that occurs during combat cleanup when your unit dies in combat, even if you have no other units on the battlefield?

Ruling: Yes, you can play Shen in response to a Deathknell trigger during combat cleanup even if you have no units remaining on the battlefield, because you still control the battlefield while the chain is open during the cleanup substeps.

Sequence:

• Units die and move to trash in Cleanup step 2
• Deathknell triggers are created and allow reactions
• While the chain is open, you still contest/control the battlefield
• You can play Shen during this window
• Contested is only removed after combat cleanup substeps complete

Nuances:

• This interaction is considered technically legal but has been given to ORD feedback for potential refinement
• The timing rules around Deathknell during combat cleanup are still being clarified
• This only applies to deaths during combat; if a unit dies from a spell during showdown, you can still play Shen there as normal