Worldgorger Dragon — ruling 1

If Worldgorger Dragon leaves the battlefield before its enters-the-battlefield ability resolves, the "leaves-the-battlefield" ability will trigger and resolve first. It won't return anything. Then the enters-the-battlefield ability will exile all other permanents you control indefinitely.

Worldgorger Dragon — ruling 2

If an Aura is exiled with Worldgorger Dragon and then returns to the battlefield, the player who controls the Aura as it enters the battlefield chooses what it will enchant. An Aura put onto the battlefield this way doesn't target anything (so it could be attached to an opponent's permanent with hexproof, for example), but the Aura's enchant ability restricts what it can be attached to. If the Aura can't legally be attached to anything, it stays exiled. It can't enter the battlefield enchanting a permanent that enters the battlefield at the same time.

Worldgorger Dragon : règles, fonctionnement et interactions (MTG)

Worldgorger Dragon is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Flying, trample When this creature enters, exile all other permanents you control. When this creature leaves the battlefield, return the exiled cards to the battlefield under their owners' control.

How it works : Worldgorger Dragon

Original English text — Wizards of the Coast / Scryfall

#1December 8, 2022· Wizards of the Coast
If Worldgorger Dragon leaves the battlefield before its enters-the-battlefield ability resolves, the "leaves-the-battlefield" ability will trigger and resolve first. It won't return anything. Then the enters-the-battlefield ability will exile all other permanents you control indefinitely.
No other card is named in this ruling.
#2December 8, 2022· Wizards of the Coast
If an Aura is exiled with Worldgorger Dragon and then returns to the battlefield, the player who controls the Aura as it enters the battlefield chooses what it will enchant. An Aura put onto the battlefield this way doesn't target anything (so it could be attached to an opponent's permanent with hexproof, for example), but the Aura's enchant ability restricts what it can be attached to. If the Aura can't legally be attached to anything, it stays exiled. It can't enter the battlefield enchanting a permanent that enters the battlefield at the same time.
No other card is named in this ruling.