Canoptek Tomb Sentinel doesn't trigger.

[remote gazelle]

Canoptek Tomb Sentinel doesn't Trigger when played from a graveyard by muldrotha.

[spark hinge]

I thought casting a spell from graveyard will enter stack, then after it resolves, from stack to battlefield.. so it shouldn't trigger I think.

[kind ferry]

Yea it would also need to check if it was "cast from graveyard" to work that way

See [[Archfiend's Vessel]]

[gritty spear]

https://scryfall.com/card/m21/88/archfiends-vessel

Archfiend's Vessel <:manab:292901508872273920>

Creature — Human Cleric
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Archfiend's Vessel enters the battlefield, if it entered from your graveyard or you cast it from your graveyard, exile it. If you do, create a 5/5 black Demon creature token with flying.
1/1

[remote gazelle]

But why doesn't it work with muldrotha? I cast it but nothing goes to the stack.

It works with unearthing the creature, but casting with muldrotha doesn't work.

[kind ferry]

Because when you cast it goes to the stack

And it needs to resolve from the stack

Unearth is an ability that doesn't cast and goes directly into play

[remote gazelle]

Ahhh so it makes no sense in a muldrotha deck. Because it needs to enter the bf directly without the cast

The unearth goes to the stack too and it enters when it resolves.

[kind ferry]

The unearth ability goes on the stack

This is pretty fundamental magic stuff

When you cast a spell, it goes onto the stack

(The spell itself, which in this case is the card)

While the unearth ability is on the stack, the card is still in the graveyard