Worlgorger vs Shapeshifter

[LizardKING]

Worldgorger Dragon
Creature - Nightmare Dragon 7/7
Flying, Trample.
When Worldgorger Dragon comes into play, remove all other permanents you control from the game.
When Worldgorger Dragon leaves play, return the removed cards to play under their owners' control.

Volrath's Shapeshifter
Creature - Shapeshifter 0/1
As long as Volrath's Shapeshifter is in play and the top card of your graveyard is a creature card, Volrath's Shapeshifter has the full text of that card, and has '2: Discard a card from your hand.' (Volrath's Shapeshifter has that card's name, mana cost, color, types, abilities, power and toughness.)
2: Discard a card from your hand.  
 

I would like to ask two questions about the interactions that may occur between these two cards :

1-WGD is the top card in the graveyard, I play VS. Am I right to say that VS just becomes a 7/7 flying trample creature without WGD's CIP abilities stacking ?

2-VS is in play, WGD in the top card in the graveyard. I cast Animate Dead for WGD. What is happening ?

Thanks for your answers.

[Toad]

1-WGD is the top card in the graveyard, I play VS. Am I right to say that VS just becomes a 7/7 flying trample creature without WGD's CIP abilities stacking ?

VS comes into play as a WGD. The WGD trigger goes on the stack.

2-VS is in play, WGD in the top card in the graveyard. I cast Animate Dead for WGD. What is happening ?

WGD comes into play enchanted by the Animate Dead. CIP goes on the stack. At this moment, the VS is not a WGD anymore. All your permanents leave play, including the VS and the Animate Dead. WGD goes to the graveyard. All your permanents return play, including VS and Animate Dead. VS enters play as a WGD. Two triggers go on the stack : Animate Dead and WGD.

Then you keep going, some stuff happen depending on how you stacked both triggers, It's quite easy to make a proper stack and I'm quite lazy.

Note that you could have refrained from posting this question on both TheManaDrain and our french forums

[Jujulautre]

Note that you could have refrained from posting this question on both TheManaDrain and our french forums

I was thinking the same; and don't want to resolve this complicated stack

[LizardKING]

Toad, you made a point here...but frankly speaking, the answer given on the french forum was less than satisfying, especially concerning point 2. As my concern was precisely about how to stack properly in order not to break the loop, I decided to ask this to experts.

[Jacob Orlove]

If you just want to go off, stack shapeshifter-WGD (s-WGD) below animate dead. That gives you the infinite loop, but as soon as you end the loop, all your permanents will disappear.

If you stack s-WGD on top, you get the following results:

s-WGD resolves, removing everything from play. Animate fails to resolve, as it is not in play. You have a 7/7 and nothing else. When it leaves play, you can do the animate dead loop if you want.

[LizardKING]

Now it is clear. Thx Jacob.