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.
610.3a If the specified event has already occurred when the initial one-shot effect would cause the object to change zones, the object doesn’t move.
610.3b An object returned to the battlefield this way returns under its owner’s control unless otherwise specified.
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:
Private Mod Note
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Why bother with mere rulings when so many answers can be found in the Rules?
Because the Angel does not say otherwise, the exiled permanents are returned under their Owner's control. Since you own Vona, you will get it back. Here is the rule for it:
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.
610.3a. If the specified event has already occurred when the initial one-shot effect would cause the object to change zones, the object doesn't move. 610.3b. An object returned to the battlefield this way returns under its owner's control unless otherwise specified.
Note that if the Harnessed Lightning is cast in response to the angel's ETB trigger (after the angel resolves, before Vona is exiled), then the angel's trigger won't do anything.
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.
610.3a. If the specified event has already occurred when the initial one-shot effect would cause the object to change zones, the object doesn't move.
610.3b. An object returned to the battlefield this way returns under its owner's control unless otherwise specified.
Two Score, Minus Two or: A Stargate Tail
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