The Commonwealth

1 Celestial Dominion: four types that count#

The first trait to know is Celestial Dominion: "Takes 70% less damage from every Type except Shadow, Light, Cosmic and Chaos." The game's data says the cut also applies to attacks with no type.

That turns the usual type chart on its head. On the chart, Faith, Nature and Storm are the only types strong against Shadow or Light, but all three lose 70% of their damage here. Shadow, Light and Cosmic are only neutral on the chart, yet they are the types that make progress. Wind is weak against both of The Commonwealth's types and Metal against one, so those balls are best kept for other floors.

2 The three Laws of damage#

Three Laws reward exactly those types, and each one leaves something behind for the next attack:

• Law of Space: "Takes 20% more damage from Shadow attacks. On Shadow attack: Gains 1 stack of Starshard."
• Law of the Stars: "Takes 20% more damage from Light attacks. On Light attack: Gains Light Strike."
• Law of the Cosmos: "Takes 20% more damage from Cosmic attacks. On Cosmic attack: Gains 1 stack of Starstruck."

What they leave behind:

• Starshard: "Takes 5% more damage per stack (max 4). Lasts for the next 4 attacks; gaining a stack refreshes it." Repeated Shadow attacks build it up to 20% on every hit.
• Light Strike: "The next attack deals 20% more damage." It works for an attack of any type.
• Starstruck: "Takes 20% increased damage from the next attack, triple it if the attack type is Light or Shadow." A Cosmic attack followed by a Light or Shadow attack sets up the bigger bonus.

Mixing the three types in sequence keeps a bonus waiting for almost every hit.

3 Law of the Inevitable: unlocking Chaos#

Chaos is the fourth type that escapes Celestial Dominion, but at first it does nothing. Law of the Inevitable reads "Immune to Chaos. Loses 1 stack when a Shadow, Light or Cosmic Ultimate is landed on it (one of each Type). When the last stack is lost, becomes Abyssal Descension."

The Law starts with 3 stacks. To break it, the party needs to land an Ultimate from a Shadow ball, one from a Light ball and one from a Cosmic ball. A second Ultimate of the same type doesn't count. Each raider has only three Multis and Ults for the whole raid, so it helps to agree beforehand who brings which type.

Once it breaks, The Commonwealth gains Abyssal Descension: "Takes 25% more damage from Chaos attacks, plus 5% more for every 20% of max HP lost." The game's data caps the extra at four steps, so the Chaos bonus grows from 25% to at most 45% as The Commonwealth's HP falls. Chaos balls held back for the second half of the fight do the most damage.

4 Eternal Commonwealth: the second life#

The first time its HP runs out, Eternal Commonwealth fires: "When defeated: Restores 25% of max HP and gains Last Stand instead." The Commonwealth comes back with 237,500 HP, a quarter of 950,000. This happens only once.

Last Stand then reads "On attack: Heals 5% of max HP (up to 25% of max HP)." Each attack your balls make on it heals it by 47,500, but never above 237,500. In practice a hit has to do more than 47,500 to make lasting progress, and a few strong hits finish the job far better than many small ones.

Counting both lives, the party has to deal at least 1,187,500 damage, plus whatever Last Stand heals back.

5 A fight in order#

The Laws suggest a shape for the fight:

1. Open with Shadow, Light and Cosmic balls, mixing the types so Starshard, Light Strike and Starstruck stay up.
2. Land a Shadow, a Light and a Cosmic Ultimate as early as is practical, to break Law of the Inevitable.
3. Bring in Chaos once Abyssal Descension is up, ideally after The Commonwealth has lost a good share of its HP.
4. Keep strong hits in reserve for the second life, where anything under 47,500 is healed straight back.

6 Drops#

The Commonwealth drops Sword of the Fallen Stars, ✦✦✦✦, Cosmic, 17,000 attack and 2,000 defense. Its effect reads "On hit: Apply 4 stacks of Starshard, 2 stacks of Starstruck, Law of Space and Law of the Cosmos." It carries two of The Commonwealth's own Laws onto any Mymic it hits, along with the bonuses that go with them.

Each kill gives everyone in the party their own chance at it. The game's Atlas lists 0.25% per kill for Sword of the Fallen Stars.

Sword of the Fallen Stars

The game's data lists The Commonwealth as a 3★ boss but doesn't place it on a numbered floor. See Special bosses for the other unusual 3★ fights and Status effects for Starshard, Starstruck and the rest.

7 On polbielytics#

The Commonwealth has its own page with every Law in full.

8 Sources#

1. The game's raid catalog: rank, level, types, HP and floors.
2. Type matchups: the game's own type list.