Nephalia

At the beginning of your end step, mill seven cards. Then return a card at random from your graveyard to your hand.
Whenever chaos ensues, return target card from your graveyard to your hand.

Planechase Anthology Planes

At the beginning of your end step, put the top seven cards of your library into your graveyard. Then return a card at random from your graveyard to your hand.
Whenever you roll {Chaos}, return target card from your graveyard to your hand.

Planechase 2012 Planes

At the beginning of your end step, put the top seven cards of your library into your graveyard. Then return a card at random from your graveyard to your hand.
Whenever you roll chaos, return target card from your graveyard to your hand.

Nephalia’s first ability doesn’t target any card, and players don’t get priority to cast spells or activate abilities in between putting cards into your graveyard and choosing a card to return.