Version 2.1 of Honkai: Star Rail introduced two additional Planar Ornament sets, available in the new World 9 of the Simulated Universe. These sets, ‘Sigonia, the Unclaimed Desolation’ and ‘Izumo Gensei and Takama Divine Realm’, each offer powerful effects but require specific conditions for maximum effectiveness. Let’s delve into how these two sets function and who can make the most of their effects.

Sigonia, the Unclaimed Desolation

First up is Sigonia, which grants a 4% increase in CRIT Rate as its initial effect. Though seemingly modest, this boost exceeds the value of a single Subsidiary Stat (substat) roll in CRIT Rate. Sigonia’s main strength lies in its second effect, which grants the wearer a 4% boost in CRIT DMG with each defeated enemy, stacking up to 10 times for a total increase of 40% CRIT DMG.

While this offers unparalleled damage potential for CRIT units, achieving maximum stacks by defeating 10 enemies can prove challenging. Although the wearer does not need to personally defeat the enemies, efficiently maxing out the conditions can really only be done in Pure Fiction. Pure Fiction, with its abundance of weak enemies, can easily allow units to achieve 10 stacks all before Wave 1 ends and before facing the bosses.

Outside of Pure Fiction, Sigonia’s utility diminishes but may still see limited uses against bosses such as Abundant Ebon Deer and Swarm: True Sting, which continuously spawns smaller enemy targets. However, unlike Pure Fiction, it can take many waves before Sigonia is fully stacked, significantly reducing its power. When not fully stacked, Sigonia’s damage potential falls below the likes of ‘Rutilant Arena’ and ‘Inert Salsotto’.

In Pure Fiction scenarios, Sigonia shines brightest for CRIT Erudition units such as Herta, Himeko, and Argenti. However, for supports such as Bronya or Sparkle, whose buffs rely on CRIT DMG, ‘Broken Keel’ remains the superior choice even over a fully stacked Sigonia.

Izumo Gensei and Takama Divine Realm

Next up is Izumo, which provides the same 12% ATK as ‘Space Sealing Station’ and ‘Firmament Frontline: Glamoth’. In addition, Izumo also provides a 12% CRIT Rate for the wearer, so long as at least one ally in the party follows the same Path. This is an extremely powerful set and presents a considerable upgrade for units accustomed to ‘Rutilant Arena’ and ‘Inert Salsotto’.

While a 4% CRIT Rate increase may seem marginal compared to Rutilant and Inert, the overall ATK boost often outweighs specific damage increases for most units. This, of course, won’t be the case for units with already ample ATK such as Jingliu or low ATK scaling like Blade.

Unfortunately, similarly to Sigonia, Izumo’s effects come with somewhat restrictive conditions. When it comes to duplicate Path pairings, not many options springs to mind. Preservation and Abundance characters are typically run solo in each party. Multiple Harmony characters are often paired together but none can make use of ATK and CRIT Rate. Notable Destruction pairings like Jinliu and Blade prefer Rutilant Arena or Inert Salsotto.

As for units that can make use of Izumo, Erudition characters like Himeko, Argenti, and Herta are decent candidates due to their preference for ATK and CRIT. However, running multiple Erudition characters is usually best reserved for Pure Fiction, where Sigonia outshines Izumo on equal substats. For Hunt, the only decent pairing would be Topaz and Dr. Ratio, both of whom can definitely utilize Izumo.

Nihility units generally do not care about CRIT, with Acheron being the notable exception. Acheron greatly benefits from Izumo’s stats and easily fulfills its conditions due to her kit. Her Ascension 4 Trace passive greatly increases all her abilities' damage when there are 1 or 2 additional Nihility units on her team, making Izumo her best option. Another Nihility that can make use of the CRIT Rate is Welt, who can often be seen accompanying Acheron.

Conclusion

While Sigonia and Izumo are very powerful sets, their effectiveness is somewhat hindered by their niche conditions, likely for the sake of maintaining balance. For players operating on a Trailblaze Power budget, it may prove more efficient to farm World 3 (Space Sealing Station & Fleet of the Ageless) or World 7 (Rutilant Arena & Broken Keel) for more universally applicable sets, and then use Synthesize to craft Sigonia and Izumo. However, World 9 remains a great option for those that want to focus on Pure Fiction, as the meta damage dealers can utilize both Sigonia and Izumo well. The power disparity between Sigonia and Izumo is not too significant, with the choice often boiling down to substats rolled. Hopefully in the future more units or game modes will be introduced to encourage broader usage of Sigonia and Izumo.