Vesuvan Shapeshifter+Harmonic Sliver Vs 2 E Plagues.

[RoddyVR]

another question about Harmonic Sliver and Engeneered Plagues, this time with a Vesuvan shapeshifter in play.

If there are 2 E Plagues set to sliver in play and i have a face down Vesuvan Shapeshifter in play,

if i cast a Harmonic Sliver, it would come into play as a -1/-1 sliver with "when comes into play destroy an enchantment" on it, targeting one of the E plagues.
now, before the sliver dies to being a -1/-1, could i morph the Shapeshifter into another Harmonic Sliver (which this time would have 2 "destroy an enchantment effects on it).

last time i asked a similar question, i was told that because what i was trying to do used the stack, the harmonic would die before i got a chance to do anything.
but Morphing doesnt use the stack as far as i know, so would the shapeshifter be "fast enough" to copy the Harmonic before it dies off.

and if it can copy the harmonic, then what would happen to it? would it become a -1/-1 sliver also (or would it become a 0/0), and die too, or even a 1/1 (seems unlikely).

i guess the question boils down to when can i morph?

[calosso]

no for 2 reasons.

1. you cannot respond to the -1/-1

2. you have to play shapeshifter for it to have the come in to play ability of the harmonic sliver

[Tacosnape]

502.26a - Morph is a static ability that functions in any zone from which you could play the card it's on, and the morph effect works any time the card is face down. "Morph [cost]" means "You may play this card as a 2/2 face-down creature, with no text, no name, no subtypes, no expansion symbol, and no mana cost by paying {3} rather than its mana cost." Any time you could play an instant, you may show all players the morph cost for any face-down permanent you control, pay that cost, then turn the permanent face up. This action does not use the stack.

That answers the question of when you can Morph. So while Morph does not use the stack or cause a change in priority, you still have to have priority to turn something face-up.

[ninjabear]

2. you have to play shapeshifter for it to have the come in to play ability of the harmonic sliver

Yes, that's important. Morphing Vesuvan Shapeshifter won't trigger "comes into play" abilities, but it will only trigger "when this creatue is turned face up" triggers. If there was an Harmonic Sliver already on the table, and you hard cast Vesuvan Shapeshifter (not morph), it will trigger the "Comes into play" abilities, but not the "When this creatue is turned face up" ones.