The Akroan War — ruling 1

If The Akroan War leaves the battlefield before its first ability resolves, you won't gain control of the creature at all.

The Akroan War — ruling 2

If a creature can't attack for any reason (such as being tapped or having come under that player's control that turn), then it doesn't attack. If there's a cost associated with having it attack, the player isn't forced to pay that cost, so it doesn't have to attack in that case either.

The Akroan War — ruling 3

Because a Saga isn't sacrificed until after its last ability has resolved, you still control the creature you took with The Akroan War's first ability while the last ability is resolving.

The Akroan War — ruling 4

If the creature you took with The Akroan War's first ability has an ability that triggers when you sacrifice The Akroan War, you control the resulting trigger. If it has an ability that triggers when The Akroan War is put into a graveyard "from anywhere," check whether that ability should trigger only after the creature's former controller has regained control of it.

The Akroan War — ruling 5

As a Saga enters the battlefield, its controller puts a lore counter on it. As your precombat main phase begins (immediately after your draw step), you put another lore counter on each Saga you control. Putting a lore counter on a Saga in either of these ways doesn't use the stack.

The Akroan War — ruling 6

Each symbol on the left of a Saga's text box represents a chapter ability. A chapter ability is a triggered ability that triggers when a lore counter that is put on the Saga causes the number of lore counters on the Saga to become equal to or greater than the ability's chapter number. Chapter abilities are put onto the stack and may be responded to.

The Akroan War — ruling 7

A chapter ability doesn't trigger if a lore counter is put on a Saga that already had a number of lore counters greater than or equal to that chapter's number. For example, the third lore counter put on a Saga causes the III chapter ability to trigger, but I and II won't trigger again.

The Akroan War — ruling 8

Once a chapter ability has triggered, the ability on the stack won't be affected if the Saga gains or loses counters, or if it leaves the battlefield.

The Akroan War : règles, fonctionnement et interactions (MTG)

The Akroan War 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 this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I — Gain control of target creature for as long as this Saga remains on the battlefield. II — Until your next turn, creatures your opponents control attack each combat if able. III — Each tapped creature deals damage to itself equal to its power.

How it works : The Akroan War

Original English text — Wizards of the Coast / Scryfall

#1January 24, 2020· Wizards of the Coast
If The Akroan War leaves the battlefield before its first ability resolves, you won't gain control of the creature at all.
No other card is named in this ruling.
#2January 24, 2020· Wizards of the Coast
If a creature can't attack for any reason (such as being tapped or having come under that player's control that turn), then it doesn't attack. If there's a cost associated with having it attack, the player isn't forced to pay that cost, so it doesn't have to attack in that case either.
No other card is named in this ruling.
#3January 24, 2020· Wizards of the Coast
Because a Saga isn't sacrificed until after its last ability has resolved, you still control the creature you took with The Akroan War's first ability while the last ability is resolving.
No other card is named in this ruling.
#4January 24, 2020· Wizards of the Coast
If the creature you took with The Akroan War's first ability has an ability that triggers when you sacrifice The Akroan War, you control the resulting trigger. If it has an ability that triggers when The Akroan War is put into a graveyard "from anywhere," check whether that ability should trigger only after the creature's former controller has regained control of it.
No other card is named in this ruling.
#5January 24, 2020· Wizards of the Coast
As a Saga enters the battlefield, its controller puts a lore counter on it. As your precombat main phase begins (immediately after your draw step), you put another lore counter on each Saga you control. Putting a lore counter on a Saga in either of these ways doesn't use the stack.
No other card is named in this ruling.
#6January 24, 2020· Wizards of the Coast
Each symbol on the left of a Saga's text box represents a chapter ability. A chapter ability is a triggered ability that triggers when a lore counter that is put on the Saga causes the number of lore counters on the Saga to become equal to or greater than the ability's chapter number. Chapter abilities are put onto the stack and may be responded to.
No other card is named in this ruling.
#7January 24, 2020· Wizards of the Coast
A chapter ability doesn't trigger if a lore counter is put on a Saga that already had a number of lore counters greater than or equal to that chapter's number. For example, the third lore counter put on a Saga causes the III chapter ability to trigger, but I and II won't trigger again.
No other card is named in this ruling.
#8January 24, 2020· Wizards of the Coast
Once a chapter ability has triggered, the ability on the stack won't be affected if the Saga gains or loses counters, or if it leaves the battlefield.
No other card is named in this ruling.
#9January 24, 2020· Wizards of the Coast
If multiple chapter abilities trigger at the same time, their controller puts them on the stack in any order. If any of them require targets, those targets are chosen as you put the abilities on the stack, before any of those abilities resolve.
No other card is named in this ruling.
#10January 24, 2020· Wizards of the Coast
Removing lore counters won't cause a previous chapter ability to trigger. If lore counters are removed from a Saga, the appropriate chapter abilities will trigger again when the Saga receives lore counters.
No other card is named in this ruling.
#11January 24, 2020· Wizards of the Coast
Once the number of lore counters on a Saga is greater than or equal to the greatest number among its chapter abilities, the Saga's controller sacrifices it as soon as its chapter ability has left the stack, most likely by resolving or being countered. This state-based action doesn't use the stack.
No other card is named in this ruling.