712.4c states the following:

712.4c If an effect can find the new object that a melded permanent becomes as it leaves the battlefield, it finds both cards. (See rule 400.7.) If that effect causes actions to be taken upon those cards, those actions are taken upon each of them.

Example: False Demise is an Aura with the ability “When enchanted creature dies, return that card to the battlefield under your control.“ A Chittering Host enchanted by False Demise dies. The triggered ability returns both Midnight Scavengers and Graf Rats to the battlefield.

Example: Otherworldly Journey is an instant that reads “Exile target creature. At the beginning of the next end step, return that card to the battlefield under its owner’s control with a +1/+1 counter on it.” A player casts Otherworldly Journey targeting Chittering Host, a melded permanent. Chittering Host is exiled. At the beginning of the next end step, Midnight Scavengers and Graf Rats are both returned to the battlefield, each with a +1/+1 counter on it.

If we have our Chittering Host and it is enchanted by Flickerform, does this mean when the two creatures return after they should BOTH be enchanted by Flickerform? Does the controller just pick one to receive the aura and the other doesn't?

Hi,

It's covered by this rule:

303.4d An Aura can’t enchant itself. If this occurs somehow, the Aura is put into its owner’s graveyard. An Aura that’s also a creature can’t enchant anything. If this occurs somehow, the Aura becomes unattached, then is put into its owner’s graveyard. (These are state-based actions. See rule 704.) An Aura can’t enchant more than one object or player. If a spell or ability would cause an Aura to become attached to more than one object or player, the Aura’s controller chooses which object or player it becomes attached to.

The Flickerform would try to attach itself to Graf Rats and Midnight Scavengers, so you choose one of the two creatures to attach it to, and it becomes attached to that creature. It does not become attached to both creatures.

Thanks,
Nathan Long
Magic Rules NetRep