Invasion of Kylem // Valor's Reach Tag Team — ruling 1

The member of World's Greatest Valor's Reach Tag Team and the other creature token don't have to be attacking the same player, planeswalker, or battle for the ability to trigger.

Invasion of Kylem // Valor's Reach Tag Team — ruling 2

The tokens' triggered ability also works if a nontoken creature somehow gains it. For example, if a nontoken creature becomes a copy of the token and then attacks alongside a creature token, the ability will trigger.

Invasion of Kylem // Valor's Reach Tag Team — ruling 3

Sieges each have an intrinsic triggered ability. That ability is "When the last defense counter is removed from this permanent, exile it, then you may cast it transformed without paying its mana cost."

Invasion of Kylem // Valor's Reach Tag Team — ruling 4

As a Siege enters the battlefield, its controller chooses an opponent to be its protector.

Invasion of Kylem // Valor's Reach Tag Team — ruling 5

A Siege's controller can't be its protector. If a Siege's protector ever gains control of it, they choose a new player to be its protector. This is a state-based action.

Invasion of Kylem // Valor's Reach Tag Team — ruling 6

If a non-battle permanent that is already on the battlefield become a copy of a Siege, its controller chooses one of their opponents to be that battle's protector. However, it will most likely be put into its owner's graveyard because it has no defense counters (see below).

Invasion of Kylem // Valor's Reach Tag Team — ruling 7

A battle's "defense" is displayed in the bottom right corner of the card. A battle enters the battlefield with that number of defense counters. If another permanent enters the battlefield as a copy of a battle, it also enters with that number of defense counters.

Invasion of Kylem // Valor's Reach Tag Team — ruling 8

Only creatures controlled by a battle's protector can block creatures that are attacking that battle. This means a Siege's controller can never assign creatures to block for it.

Invasion of Kylem // Valor's Reach Tag Team : règles, fonctionnement et interactions (MTG)

Invasion of Kylem // Valor's Reach Tag Team 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

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.) When this Siege enters, up to two target creatures each get +2/+0 and gain vigilance and haste until end of turn. Create two 3/2 red and white Warrior creature tokens with "Whenever this token and at least one other creature token attack, put a +1/+1 counter on this token."

How it works : Invasion of Kylem // Valor's Reach Tag Team

Original English text — Wizards of the Coast / Scryfall

#1April 14, 2023· Wizards of the Coast
The member of World's Greatest Valor's Reach Tag Team and the other creature token don't have to be attacking the same player, planeswalker, or battle for the ability to trigger.
No other card is named in this ruling.
#2April 14, 2023· Wizards of the Coast
The tokens' triggered ability also works if a nontoken creature somehow gains it. For example, if a nontoken creature becomes a copy of the token and then attacks alongside a creature token, the ability will trigger.
No other card is named in this ruling.
#3April 14, 2023· Wizards of the Coast
Sieges each have an intrinsic triggered ability. That ability is "When the last defense counter is removed from this permanent, exile it, then you may cast it transformed without paying its mana cost."
No other card is named in this ruling.
#4April 14, 2023· Wizards of the Coast
As a Siege enters the battlefield, its controller chooses an opponent to be its protector.
No other card is named in this ruling.
#5April 14, 2023· Wizards of the Coast
A Siege's controller can't be its protector. If a Siege's protector ever gains control of it, they choose a new player to be its protector. This is a state-based action.
No other card is named in this ruling.
#6April 14, 2023· Wizards of the Coast
If a non-battle permanent that is already on the battlefield become a copy of a Siege, its controller chooses one of their opponents to be that battle's protector. However, it will most likely be put into its owner's graveyard because it has no defense counters (see below).
No other card is named in this ruling.
#7April 14, 2023· Wizards of the Coast
A battle's "defense" is displayed in the bottom right corner of the card. A battle enters the battlefield with that number of defense counters. If another permanent enters the battlefield as a copy of a battle, it also enters with that number of defense counters.
No other card is named in this ruling.
#8April 14, 2023· Wizards of the Coast
Only creatures controlled by a battle's protector can block creatures that are attacking that battle. This means a Siege's controller can never assign creatures to block for it.
No other card is named in this ruling.
#9April 14, 2023· Wizards of the Coast
A battle can be dealt damage and be target of spells and/or abilities that target "any target."
No other card is named in this ruling.
#10April 14, 2023· Wizards of the Coast
Damage dealt to a battle causes that many defense counters to be removed from it.
No other card is named in this ruling.
#11April 14, 2023· Wizards of the Coast
A battle can be attacked by all players other than its protector. Notably, this means a Siege's controller can attack it.
No other card is named in this ruling.
#12April 14, 2023· Wizards of the Coast
If a battle has no defense counters, and it isn't the source of a triggered ability that has triggered but not yet left the stack, that battle is put into its owner's graveyard. This is a state-based action. This doesn't cause a Siege's intrinsic triggered ability to trigger.
No other card is named in this ruling.
#13April 14, 2023· Wizards of the Coast
If a Siege never had defense counters on it (perhaps because a permanent became a copy of one), it can't have its last defense counter removed. It will be put into its owner's graveyard. You won't exile it or cast the other face.
No other card is named in this ruling.
#14April 14, 2023· Wizards of the Coast
If a token or a card that isn't represented by a transforming double-faced card becomes a copy of a Siege, it can't be cast as its triggered ability resolves. It will remain in exile. If it's a token, it will cease to exist the next time state-based actions are performed.
No other card is named in this ruling.
#15April 14, 2023· Wizards of the Coast
If a permanent that is represented by a transforming double-faced card becomes a copy of a Siege, it will be exiled as that Siege's triggered ability resolves, then it will be cast transformed. Note that this applies only to transforming double-faced cards, not to modal double-faced cards that can normally be played using either face.
No other card is named in this ruling.
#16April 14, 2023· Wizards of the Coast
In a multiplayer game, if the protector of a battle leaves the game and that battle is not currently being attacked, its controller chooses a new protector for it as a state-based action. If it is being attacked, its controller chooses a new protector for it once no creatures are attacking it. This means that it continues to be attacked and can be dealt combat damage as normal.
No other card is named in this ruling.
#17April 14, 2023· Wizards of the Coast
If a battle that's being attacked somehow stops being a battle, it is removed from combat. Similarly, if its controller changes in the middle of combat, it is removed from combat.
No other card is named in this ruling.
#18April 14, 2023· Wizards of the Coast
Battles can't attack or block, even if one also becomes a creature. If an attacking or blocking creature somehow becomes a battle in addition to being a creature, it is removed from combat.
No other card is named in this ruling.