Vertexia, Xterial and Kivalaian

From the Polandball Go WikiUpdated October 27, 2026

Vertexia, Xterial and Kivalaian are three 3★ bosses fought together on floor 6, as one encounter. Each has 800,000 HP, 2,400,000 between them. You queue a lobby for one of them, and that one becomes the leader. The leader brings one extra trait that the other two don't, and it changes how the whole fight has to be played.

Vertexia

Xterial

Kivalaian

1 The three bosses#

Vertexia is Storm and Cosmic. It has Flight, "Immune to "Mountain" attacks," which matters because Mountain is the one type strong against both of its types.
Xterial is Shadow and Chaos.
Kivalaian is Cosmic and Ice.

Each boss keeps its own traits in every lobby. Only the leader trait depends on which boss you queued for. The leader is the one to beat first, and two of the three leader traits all but force it.

2 Vertexia: Visceral Slash#

Vertexia carries two traits in every lobby:

Visceral Slash: "Every attack that isn't a Multi: Loses 1 stack. When the last stack is lost, exhausts 3 random Polbies and resets. A Multi attack resets it."
Eye of the Storm: "When a Multi resets Visceral Slash from its last stack: Unexhausts a random Polbie."

The slash starts at 3 stacks. The game's data says it counts every attack on the floor, not only attacks on Vertexia. Two ordinary attacks take it down to 1, and a third exhausts three random balls. A Multi used at that point resets the count and, through Eye of the Storm, gives a ball back. With three Multis and Ults per raider for the whole raid, a party has only so many resets to spend, so the timing matters.

Leading: Bloodlust. "Leader: When defeated, Visceral Slash passes to another Mymic." When Vertexia leads and falls, Visceral Slash and Eye of the Storm move to whichever living boss has the most HP. In a Vertexia lobby, killing Vertexia doesn't end the slash. It just changes who carries it.

3 Xterial: Overseer and Headshot#

Xterial carries five traits in every lobby:

Overseer: "Dodges 10% of Super Effective attacks, 30% of neutral attacks and 75% of resisted attacks. Never dodges Ice."
Frostbite: "Every 3,000 damage taken from Ice attacks: Gains 1 stack of Brittle." Brittle reads "Super Effective hits deal 10% bonus damage per stack."
Avalanche: "When hit by an Ice Ultimate: For every 3 stacks of Brittle, loses them and unexhausts a random Polbie."
Headshot: "Gains 1 stack per attack in a row by a Polbie with equipment Resonance. At 3 stacks, exhausts the strongest remaining Polbie. Any other attack resets it."
Culmination: "Gains 1 stack per attack that revives a Polbie. From the 5th stack on, every such attack heals this Mymic 30,000 HP."

Ice is the answer to most of this. Overseer never dodges it, Frostbite turns Ice damage into Brittle, and an Ice Ultimate then cashes in the Brittle for balls back. Ice is neutral against Xterial's Shadow and Chaos on the chart, but those hits never miss. The types strong against Xterial, Balance, Chaos, Faith, Fire and Light, still lose 10% of their attacks to Overseer.

Headshot counts attacks by balls that carry an item with a resonance type. Three in a row exhausts your strongest ball, so an attack from a ball with no item breaks the chain. Culmination punishes heavy unexhausting: the first four attacks that bring a ball back are free, and from the fifth on, each one heals Xterial 30,000 HP.

Leading: Gatekeeper. "Leader: While this Mymic is undefeated, other Mymics take 90% less damage." In an Xterial lobby, Vertexia and Kivalaian barely take damage until Xterial is down.

4 Kivalaian: Rift and Black Hole#

Kivalaian carries these in every lobby:

Rift: "Blocks the next X hits. When a Super Effective hit is blocked: Exhausts a random Polbie and gains 1 stack." It starts with 2 stacks.
White Hole: "When the last stack of Rift is spent: Unexhausts a random Polbie."
Black Hole: "Gains 1 stack per Ultimate in a row. At 2 stacks, gains 3 stacks of Event Horizon and resets."
Event Horizon: "On attack: Exhausts a random Polbie and loses 1 stack."
Loophole: "When below 50% HP: Gains 3 stacks of Rift and becomes Unraveling."
Unraveling: "Takes 25% more damage from Super Effective attacks. On Ultimate: Gains 1 stack of Shatterpoint." Shatterpoint reads "I take 10% more damage per stack from Ultimate Attacks."

Rift turns the usual logic upside down. A hit that isn't Super Effective spends a stack of Rift, but a Super Effective hit that gets blocked adds a stack and costs you a ball. The way through is to open with neutral or resisted hits until Rift is gone, which also earns a ball back from White Hole. Loophole puts 3 stacks back once Kivalaian drops below half HP, so the same thing happens a second time.

Event Horizon goes off when your balls attack Kivalaian, not when it acts. Two Ultimates in a row on Kivalaian give it 3 stacks, and each of the next three attacks on it exhausts a random ball. Any attack that isn't an Ultimate resets the Black Hole count.

Leading: Gravity Well. "Leader: While this Mymic has Rift, single-target attacks are redirected to it." In a Kivalaian lobby, ordinary attacks and Ultimates all go to Kivalaian while it has Rift. Multis aren't redirected.

5 Types#

On the type chart:

Vertexia (Storm, Cosmic): Mountain is strong against both types, but Flight makes Mountain attacks miss. Faith, Storm and Wind are strong against one. Agriculture, Chaos, Cosmic, Energy, Fire and Water are weak against it.
Xterial (Shadow, Chaos): Balance, Chaos, Faith, Fire and Light are strong. Agriculture, Metal, Shadow and Wind are weak.
Kivalaian (Cosmic, Ice): Chaos, Cosmic, Light, Metal, Mountain and Storm are strong. Energy and Water are weak against both types.

Chaos, Faith, Light and Storm each score well against two of the three. Faith, Light and Storm are neutral against the third, while Chaos is weak against Vertexia.

6 Drops#

Each boss drops its own ✦✦✦✦ item, and each kill gives everyone in the party their own chance at it. The game's Atlas lists 0.25% per kill for each:

The Harvester from Vertexia: Cosmic, 15,000 attack, 3,000 defense, for Balance, Chaos, Storm or Cosmic balls only. "Double damage to Mymics weak to Cosmic or Storm. On hit: Unexhaust a random Polbie (once per floor)"
Silent Assassin from Xterial: Balance, 18,555 attack, 0 defense, for Chaos or Shadow balls only. "Attacks against the strongest Mymic on the floor are always Super Effective. On hit: Apply 3 stacks of Inked"
Cosmic Glacialis from Kivalaian: Ice, 15,000 attack, 2,000 defense. "Attacks bypass Shield and ignore resistance. Super Effective attacks deal 50% more damage. On hit: Apply 5 stacks of Starstruck"