Torpor Orb preventing Moonshadow from triggering

[K7pyk3M5AE2X3]

Unconfirmed but happened in three games now tonight, but [[torpor orb]] is preventing the [[moonshadow]] from triggering. My gut is it's checking more than "creatures entering".

[github-actions]

Moonshadow - (Gatherer) (Scryfall) (EDHREC)

{B}
Creature — Elemental
7/7
Menace
This creature enters with six -1/-1 counters on it.
Whenever one or more permanent cards are put into your graveyard from anywhere while this creature has a -1/-1 counter on it, remove a -1/-1 counter from this creature.

[muz]

Can you provide more information about the full board state and interactions you had. I get that there was a Torpor Orb on the board with a Moonshadow, but what else was happening in the board state and what were you expecting from those interactions?

[K7pyk3M5AE2X3]

I was attacking on my own turn, my own creatures would die (not moonshadow), it wouldn't remove a counter, there was no exile affects (i.e. leyline, etc). Likewise when I would use fetch lands. It WAS working fine prior to my playing the torpor orb

[miesma]

I did a quick test locally and yes somehow [[Torpor Orb]] is preventing the Moonshadow triggers.

Test-Log

Ex: 13:49, T8.M1: Torpor Orb [061]: Prevented ability of Moonshadow [6a8] from triggering.

[[Elesh Norn, Mother of Machines]] Does the same. But does not double the trigger (Which is correct).

Test-Log Elesh Norn

BUT the error seems to be with Moonshadow's implementation. [[Aetherworks Marvel]] 's trigger (which I would argue is similar enough to test) do not get prevented.

Test-Log Aetherworks

For some reason Moonshadow's trigger is prevented by those effects.

To be sure I tested with another creature [[Shard of the Void Dragon]] aswell to check if all such triggers on creatures are prevented
which is not the case.

Test-Log Shard

[github-actions]

Torpor Orb - (Gatherer) (Scryfall) (EDHREC)

{2}
Artifact
Creatures entering don't cause abilities to trigger.

Elesh Norn, Mother of Machines - (Gatherer) (Scryfall) (EDHREC)

{4}{W}
Legendary Creature — Phyrexian Praetor
4/7
Vigilance
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering don't cause abilities of permanents your opponents control to trigger.

Aetherworks Marvel - (Gatherer) (Scryfall) (EDHREC)

{4}
Legendary Artifact
Whenever a permanent you control is put into a graveyard, you get {E} (an energy counter).
{T}, Pay six {E}: Look at the top six cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Shard of the Void Dragon - (Gatherer) (Scryfall) (EDHREC)

{4}{B}{B}{B}
Creature — C'tan
7/7
Flying
Spear of the Void Dragon — Whenever this creature attacks, each opponent sacrifices a nonland permanent of their choice.
Matter Absorption — Whenever an artifact is put into a graveyard from the battlefield or is put into exile from the battlefield, put two +1/+1 counters on this creature.

[K7pyk3M5AE2X3]

I hate to suggest it but did someone on the Torpor Orb implementation not look up the guru text, i.e. "Creatures entering" is "[battlefield]" implied and, confirmed in guru text. Not the other cards (above) explicitly say zone whereas older printings of torpor orb to do. Still, that wouldn't explain the fetch lands not triggering it but just throwing it out there.

[matoro]

introduced in 49d292a

[miesma]

Yeah. Torpor Orb itself is not the problem here.
The usage of ZONE_CHANGE_BATCH in Moonshadow causes this. Kinda.
Having the return paramenter in DontCauseTriggerEffect default to true ("don't trigger" applies)
seems to be the problem for ZONE_CHANGE_BATCH.

all_match = true; (applies)
None of the filter match. all_match does not change.
return all_match (true) -> blocks trigger

This is my quick analysis of the code. I don't have deep system knowledge and could misinterpret something.

[matoro]

Fix in #15681