painter-stone-relic vs emrakul-worldspine

[Fallen_Empire]

Alright so say I'm on painter and I've combo-ed off. My opponent is on big red so their deck goes to the graveyard. The milled deck has 2x Emrakul, the Aeons Torn and 2x Worldspine Wurm that just entered the graveyard. I'm pretty sure both copies of Emrakul trigger at the same time, so in response I sac Relic of Progenitus to remove them from the game. Does that mean that in the process the Worldspine Wurms are also dealt with or do they trigger at different times?

[kombatkiwi]

Effect of card: {3}, {T}: Target player puts the top two cards of his or her library into his or her graveyard. If both cards share a color, repeat this process.

With the painter combo all cards are the same color so this process will continue until your opponent has no cards left in their library.
Both Emrakul and Worldspine Wurm have triggered abilities (unlike e.g. Progenitus which works slightly differently) with the same trigger condition. Nobody has priority while the Grindstone ability is resolving so these abilities will not go onto the stack until your opponents entire deck is in the graveyard.

Because all 4 of these abilities trigger at the same time, the opponent (who controls the abilities) can put them on the stack in the order that they choose, but all 4 abilities must go on the stack at once. Before any of them resolve you can activate Relic to exile your opponent's graveyard (including Worldspine and Emrakul). When the triggered abilities resolve they will not find any Emrakul or Worldspine to shuffle into the library.

[Fallen_Empire]

With the painter combo all cards are the same color so this process will continue until your opponent has no cards left in their library.
Both Emrakul and Worldspine Wurm have triggered abilities (unlike e.g. Progenitus which works slightly differently) with the same trigger condition. Nobody has priority while the Grindstone ability is resolving so these abilities will not go onto the stack until your opponents entire deck is in the graveyard.

Because all 4 of these abilities trigger at the same time, the opponent (who controls the abilities) can put them on the stack in the order that they choose, but all 4 abilities must go on the stack at once. Before any of them resolve you can activate Relic to exile your opponent's graveyard (including Worldspine and Emrakul). When the triggered abilities resolve they will not find any Emrakul or Worldspine to shuffle into the library.

Great explanation, many thanks!