Jade Seedstones // Jadeheart Attendant — ruling 1

You choose how many targets the first ability of Jade Seedstones has and how the counters will be distributed as that ability is put on the stack. Each target must receive at least one counter.

Jade Seedstones // Jadeheart Attendant — ruling 2

If some of the creatures are illegal targets as the first ability of Jade Seedstones tries to resolve, the original distribution of counters still applies and the counters that would have been put on the illegal targets are lost. They won't be put instead on a legal target.

Jade Seedstones // Jadeheart Attendant — ruling 3

In some unusual cases, multiple cards may be exiled to craft Jadeheart Attendant. For example, if an effect makes Jade Seedstones a copy of a permanent with a craft ability that requires multiple components, the copy effect will expire as Jade Seedstones leaves the battlefield and it will return as Jadeheart Attendant. The enters-the-battlefield ability will count all the exiled cards, and you'll gain life equal to their total mana values.

Jade Seedstones // Jadeheart Attendant — ruling 4

The back faces of some cards with craft refer to cards "used to craft" it. This refers to the cards exiled as part of the cost of the craft ability of the front face. Those cards are considered to be "used to craft" that permanent as long as they remain exiled and the permanent remains on the battlefield, even if the permanent's controller changes or some of its characteristics change (because of a copy effect, for example.)

Jade Seedstones // Jadeheart Attendant — ruling 5

If the materials required include multiple objects, you may exile some of them from among permanents you control and the rest from among cards in your graveyard. You don't have to choose all permanents or all cards from your graveyard.

Jade Seedstones // Jadeheart Attendant — ruling 6

You may exile tokens you control as part of the materials required. However, because they aren't cards and won't stay in exile, any abilities that refer to what you "used to craft" the back faces won't refer to anything.

Jade Seedstones // Jadeheart Attendant — ruling 7

If a card that isn't a transforming double-faced card becomes a copy of a card with craft, it'll stay in exile if you activate the craft ability. It won't return to the battlefield.

Jade Seedstones // Jadeheart Attendant : règles, fonctionnement et interactions (MTG)

Jade Seedstones // Jadeheart Attendant is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

When this artifact enters, distribute three +1/+1 counters among one, two, or three target creatures you control. Craft with creature (, Exile this artifact, Exile a creature you control or a creature card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.) When this creature enters, you gain life equal to the mana value of the exiled card used to craft it.

How it works : Jade Seedstones // Jadeheart Attendant

Original English text — Wizards of the Coast / Scryfall

#1November 10, 2023· Wizards of the Coast
You choose how many targets the first ability of Jade Seedstones has and how the counters will be distributed as that ability is put on the stack. Each target must receive at least one counter.
No other card is named in this ruling.
#2November 10, 2023· Wizards of the Coast
If some of the creatures are illegal targets as the first ability of Jade Seedstones tries to resolve, the original distribution of counters still applies and the counters that would have been put on the illegal targets are lost. They won't be put instead on a legal target.
No other card is named in this ruling.
#3November 10, 2023· Wizards of the Coast
In some unusual cases, multiple cards may be exiled to craft Jadeheart Attendant. For example, if an effect makes Jade Seedstones a copy of a permanent with a craft ability that requires multiple components, the copy effect will expire as Jade Seedstones leaves the battlefield and it will return as Jadeheart Attendant. The enters-the-battlefield ability will count all the exiled cards, and you'll gain life equal to their total mana values.
No other card is named in this ruling.
#4November 10, 2023· Wizards of the Coast
The back faces of some cards with craft refer to cards "used to craft" it. This refers to the cards exiled as part of the cost of the craft ability of the front face. Those cards are considered to be "used to craft" that permanent as long as they remain exiled and the permanent remains on the battlefield, even if the permanent's controller changes or some of its characteristics change (because of a copy effect, for example.)
No other card is named in this ruling.
#5November 10, 2023· Wizards of the Coast
If the materials required include multiple objects, you may exile some of them from among permanents you control and the rest from among cards in your graveyard. You don't have to choose all permanents or all cards from your graveyard.
No other card is named in this ruling.
#6November 10, 2023· Wizards of the Coast
You may exile tokens you control as part of the materials required. However, because they aren't cards and won't stay in exile, any abilities that refer to what you "used to craft" the back faces won't refer to anything.
No other card is named in this ruling.
#7November 10, 2023· Wizards of the Coast
If a card that isn't a transforming double-faced card becomes a copy of a card with craft, it'll stay in exile if you activate the craft ability. It won't return to the battlefield.
No other card is named in this ruling.