Under which controller does a stolen permanent come into play after being exiled?

Question

Here's what I did on MTG Arena:

Opponent exiles my The Immortal Sun with Hostage Taker, then plays it. On my turn, I cast Ixalan's Binding targeting Immortal Sun, and then Demystify my own Ixalan's Binding. The Immortal Sun then entered the battlefield under my control.

Question 1: I thought it might work, that's why I tried it, but I don't understand why it worked. I read the rulings of Ixalan's Binding, and couldn't find something that could explain why it returned from exile under its owner's control, and not under the last controller's control. Can anyone explain the rulings behind this?

Question 2: Would flickering a stolen permanent work the same?

Answer 1

Immortal Sun enters the battlefield under your control because Ixalan's Binding creates a special one-shot effect that has its own rules treatment. When flickering an object as a regular one-shot effect, its subsequent controller depends on the card used to flicker; both "you", the controller of the effect, and "the permanent's owner" are possible, and are always specified by the card.

Ixalan's Binding doesn't specify under whose control the permanent returns to the battlefield, so by default it's the owner of the exiled permanent, namely you:

610.3. Some one-shot effects cause an object to change zones “until” a specified event occurs. A second one-shot effect is created immediately after the specified event. This second one-shot effect returns the object to its previous zone.

610.3b An object returned to the battlefield this way returns under its owner’s control unless otherwise specified.

For Flicker effects, it depends on the specific card/effect that does the flickering, both variants are possible: you, or the owner, who may or may not be you

Answer 2

When a card enters the battlefield from exile, it is put under it's owner's control unless an effect says otherwise. When a card leaves the battlefield and returns, it is treated as a new object, the control changing effects on that card were on the old object, and cards enter the battlefield under their owner's control. Since you are the owner of Immoral Sun, it comes into play under your control when it returns from exile. This is stated by the comprehensive rules here:

400.7 An object that moves from one zone to another becomes a new object with no memory of, or relation to, its previous existence. There are nine exceptions to this rule:

The card has no memory of the control your opponent had, but it's owner is a characteristic of the card, something it never loses, so it returns to its owner.

Flickering would work the same for most flicker abilities, other than those that specify who's controller the card comes into play, like Ghostly Flicker or Cloudshift which say to return the cards to the battlefield under the caster's control. This was at one point used to make temporary control effects more permanent, since the card entering as a new object would no longer have the "until end of turn" control effect from cards like Act of Treason.

Answer 3

The relevant rule here is this one:

400.7. An object that moves from one zone to another becomes a new object with no memory of, or relation to, its previous existence. There are nine exceptions to this rule: [none of which apply]

So when your Immortal Sun get's exiled and comes back, it doesn't "remember" that it was ever controlled by your opponent. And when something comes back into the game and doesn't have a controller, it's owner gains control of it.

Flicker and Cloudshift and the like will specify under whose control the permanant returns, so they are a little bit different.

Answer 4

Question 2: Yes, when a permanent is exiled and then returned to the battlefield (flicker) it is a new permanent, not the same permanent (as per the rules) and will therefore enter under its owner's control

Question 1:

from ixalan's binding card:

exile target nonland permanent an opponent controls until Ixalan's Binding leaves the battlefield.

So first of all simply put, when you demystify ixalan's binding this part would resolve, so the Immortal Sun would return to the battlefield. I get the question might be why it comes back to you and not your opponent so...

Rule 108.3 states that the owner of a card in the game is the player who started the game with it in his or her deck. The card would return to its owners control...it couldn't come back to its "controller" control because at that moment there was none.

You own Immortal Sun, your opponent casts it and gains control of the card, but not ownership, you exile and now the card is not controller by anyone anymore (after the trigger resolves, before it resolves it is under their control or else ixalan's binding wouldn't be able to target it) after it returns from exile it is now a new permanent that must enter under its owners control as there was no controller, it then becomes a permanent when it actually enters the battlefield and you become the controller.

Hope that sort of makes sense.