Operation guide: Frost-Covered Ruins
| Operation | Contracts | Guide |
| #0 (Barrenland) | Rotating Site (Day 6 and 13) |
|---|---|
| #1 (Pyrite) | Rotating Site (Day 7 and 14) |
| #2 (Blade) | Rotating Site (Day 1 and 2) |
| #3 (Cinder) | Rotating Site (Day 6) |
Frost-Covered Ruins will prove to be one of the most bothersome Rotating Sites due to the presence of two Originium Ice Crystals which periodically activates Frigid Tide to inflict cold/freeze on friendly units around it. To compound this, the Originium Zone: Cold Snap contract will make the Crystals activate their Frigid Twice slightly more than twice as fast, and the Originium Zone: Inertia contract extends the duration of Negative Statuses on friendlies; should both contracts are combined, the player's units can literally be permanently frozen!
As if those weren't enough, Frost-Covered Ruins also feature Yeti Squadron enemies who can inflict more damage against frozen targets along with some regular Reunion enemies making guest appearances, with the following are to be watch out for:
- Yeti Icecleavers and Yeti Icecleaver Leaders, really tough katana-toting winter soldiers who can cause almost triple damage against frozen targets that allows them to KO even the sturdiest of Defenders with a single hit should they are frozen, especially with the Originium Zone: Stimulus III contract. To make them more menacing, the Target: Ice Melter contracts will crank up their already high stats even further, literally making them as tough as an iceberg.
- Defense Crushers; those who had often played Lungmen Downtown will know how to feel when they are on the receiving end of their hammer, who can stun its victim every three attacks, not to mention that they have a sheer HP and DEF that makes most physical attacks barely scratch them, though their lack of RES makes them very susceptible to Arts damage. Unfortunately, that's no longer the case in Frost-Covered Ruins with the Target: Fortification Defense contracts which buffs their already high HP and DEF, as well as increasing their ASPD which allows them to stun unfortunate Operators more often, giving them some RES which removes their weakness to Arts damage, and what's worse, makes them can no longer be silenced, so nothing can stop their stunning attacks.
- Yeti Casters; while lacking their Yeti Squadron comrades' ability to do more damage on frozen targets, they can instead inflict the cold/freeze effect in every third of their ranged Arts attacks, so be mindful to them when using ranged-heavy squads or the Cold Snap and/or Inertia contracts.
- Metal Crabs; their high resilience and the lack of holes in the operation means that killing these creatures will take some time, so try to use Arts Operators or those who can deal Pure damage against them.