When 2 creatures are dying to Singularity and you control Zhonya's, can you choose which unit survives, or does the opponent choose when assigning targets?

Ruling: You choose which dying event to replace with Zhonya's. Both units die at the same time from Singularity, so you control which one Zhonya's saves.

Nuances:

• This ruling differs from cards like IR or Falling Star, which are ruled differently