2016-01-22 : Creatures that Flaying Tendrils would cause to die will be exiled instead. The game doesn’t check to see which creatures die until after Flaying Tendrils has finished resolving.

2016-01-22 : Only creatures that are on the battlefield as Flaying Tendrils resolves will get -2/-2. However, any creature that would die that turn will be exiled, even if it wasn’t on the battlefield or wasn’t a creature as Flaying Tendrils resolved.