Porphyry Nodes and Mishra's Factory

[TracerBullet]

It is the beginning of player A's turn.

Player A controls a Porphyry Nodes and a Mishra's Factory.  There are no creatures in play.


Can player A stack the Porphyry Nodes' abilities in the following order, allowing Porphyry Nodes to stay in play?

1. Clause B (If no creatures in play, sacrifice PN)

1.5 Mishra's Factory's ability (After clause A resolves)

2. Clause A (Destroy Creature with lowest power)


Thus resolving Clause A, Mishra's Factory, and Clause B in that order?  In short, would Porphyry Nodes be in play at the end of my upkeep?

[Delha]

I suspect that it is impossible to achieve the gamestate you describe. If Nodes is in play during an opponent's turn with an activated Factory as the only creature in play, once it reverts, the sacrifice ability for Nodes will trigger. I cannot offhand think of any way for Nodes to be in play at the beginning of your upkeep with no actual creatures on the table.

State trigger description listed below for reference.

603.8. Some triggered abilities trigger when a game state (such as a player controlling no permanents of a particular card type) is true, rather than triggering when an event occurs. These abilities trigger as soon as the game state matches the condition. They’ll go onto the stack at the next available opportunity. These are called state triggers. (Note that state triggers aren’t the same as state-based actions.) A state-triggered ability doesn’t trigger again until the ability has resolved, has been countered, or has otherwise left the stack. Then, if the object with the ability is still in the same zone and the game state still matches its trigger condition, the ability will trigger again

[BC]

Yeah, I'm not sure how to explain the ruling in actual judge's terms, but that doesn't work.  It might work if Nodes said "At the beginning of your upkeep, if there are no creatures on the battlefield...".  But as Nodes is worded, it will die whenever Factory isn't a creature.  Even if you could activate Factory and sac it to Nodes, there still wouldn't be any creatures on the battlefield after you sacrificed it, so Nodes would die then.

[Rico Suave]

Here is the important clause:

"When there are no creatures on the battlefield, sacrifice Porphyry Nodes."

When there are no creatures on the battlefield, this trigger will go on the stack.  When the trigger resolves, its controller must sacrifice it.  It does not care if a creature is on the battlefield after it triggers because that has no effect on whether the ability will continue to resolve.

Contrast to, say, Pestilence.  

"At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence."

This triggers at the beginning of the end step, looks to see if creatures are on the battlefield, then goes to its effect.  If there is a creature on the battlefield before this trigger resolves, then its controller will not sacrifice Pestilence.  I think you might be confusing these two effects.

But even more importantly, there is something else to consider:

Should you have Mishra's Factory animated during your opponent's turn (say, if you animated Factory to block their creature and kill it), and thus the Nodes does not trigger immediately, at the clean-up step the Mishra's Factory will cease to be a creature and the Nodes *will* trigger during the clean-up step.  Nodes will likely be sacrificed, then because there was a trigger the game will continue to a 2nd clean-up step.

Essentially, the important part is to note that Porphyry Nodes triggers when there are no creatures on the battlefield, but putting a creature onto the battlefield after it triggers will not stop that trigger from resolving.

[Delha]

I think this question has become more entertaining for me as a thought exercise than anything else. 

Here's what I've got, it ended up being a lot simpler than I initially thought:
Porphory Nodes, Mycosynth Lattice on board. Reality Ripple the Nodes to phase it out, then kill the Ornithopter somehow.

If I'm remembering things correctly, this should play out as follows.
1. Nodes phases back in on your untap.
2. Nodes finds no creatures and the sacrifice clause triggers. Since you don't get priority during untap, the trigger doesn't go onto the stack yet.
3. In your upkeep, both triggers would go on the stack, so you can order them with destroy on top.
4. Destroy trigger resolves with no targets.
5. You get priority, and can activate the Factory.
6. Sacrifice trigger resolves. Unfortunately, the it does not check the triggering condition upon resolution, and the Nodes dies anyway (as pointed out by Rico). If the sacrifice clause had an intervening if, then the Factory activation should save it.

Sorry I forgot to give the simple answer in my initial response.