Dia arrived in The First Descendant as the game’s first gunlance-wielding melee DPS Descendant, bringing an aggressive Chill-based playstyle that rewards high HP stacking and critical hit optimization. This Dia build guide will help you use her best tools and builds to efficiently maximize her burst damage.
1. How Dia Works in The First Descendant
Dia is fundamentally a melee crit-focused Descendant whose damage output scales directly with Max HP and her unique resource gauge called Delight.
Her passive ability, Frozen Delight, grants her a flat Skill Critical Hit Rate bonus of up to 45% when wielding melee weapons, calculated as Max HP × 0.13%.
- 10% Crit Rate: ~7,693 HP
- 20% Crit Rate: ~15,385 HP
- 30% Crit Rate: ~23,077 HP
- 40% Crit Rate: ~30,769 HP
- 45% Crit Rate Cap: 34,616 HP
This means you need 34,616 HP to hit the 45% critical rate cap, making HP stacking a core priority across all her builds.
Additionally, her passive grants a bonus Skill Power ratio of up to 35% at maximum Delight gauge, further rewarding active ability usage and proper resource management.
Dia’s Descendant pose.
2. How to Unlock and Research Dia
Dia requires substantial investment in farming and research before you can deploy her in The First Descendant. Below is a comprehensive list of all required research materials.
| Component | Research Time | Research Cost | Materials Required |
|---|---|---|---|
| Dia Enhanced Cells | 8 Hours | 200,000 Gold |
|
| Dia Stabilizer | 8 Hours | 200,000 Gold |
|
| Dia Spiral Catalyst | 8 Hours | 200,000 Gold |
|
| Dia (Final Assembly) | 16 Hours | 400,000 Gold |
|
Unlocking Dia involves crafting three core components (Enhanced Cells, Stabilizer, Spiral Catalyst) and obtaining her Code from completing missions. Each component requires 8 hours of research and 200,000 Gold; the final assembly requires 16 hours and 400,000 Gold.
2.1 Where to Find All Blueprints
The Dia Code is obtained by completing specific Hard and High-Risk missions:
- [Axion Plains] [Hard] – Complete “Exposed Underwater Base”
- [Sigma Sector Dropoff Operation] [High-risk] – Complete “Broken Boundary”
You can also obtain the remaining Dia Blueprints (Enhanced Cells, Stabilizer, Spiral Catalyst) from the same missions, with the highest drop chance, at 15%, being in the Exposed Underwater Base Mission.
All Dia materials.
3. All Skills and Abilities
Dia’s kit strongly rewards players who maintain melee uptime and keep her buffs rolling between mobbing waves and boss phases.
3.1 Glacial Clash (Fusion)
Dia’s first ability is her primary mobility tool and Delight generator, featuring two modes.
- Tap Cast (Glacial Clash): Dashes forward, stabbing enemies to deal initial AoE damage and inflicting Knockback.
- Hold Cast (Glacial Breakthrough): Moves forward continuously, damaging all collided enemies and applying Snowflake debuff.
Snowflake is crucial for Dia’s damage loop: enemies afflicted with Snowflake take bonus Skill Power damage when hit by melee weapons, not abilities. This synergy makes the Shadow sword her best-in-slot weapon, as its multi-hit attacks trigger Snowflake’s bonus damage multiple times per swing.
Glacial Clash has three charges with relatively short cooldowns, and holding the ability recovers Delight extremely fast, ensuring you always have maximum resources when your major cooldowns come back up.
Glacial Clash.
3.2 Ice Wall (Singular)
Ice Wall is Dia’s primary self-buff that significantly amplifies her combat effectiveness:
- Grants Defense, Skill Critical Damage, and HP Recovery
- Increases Glacial Breakthrough’s dash speed and duration
- Explodes to deal AoE damage when the buff expires
- Restores HP when the buff ends
Maintaining 100% uptime on Ice Wall’s buff is critical for smooth rotations and maximizing DPS, which requires heavy investment into Skill Cooldown reduction through modules and Ancestor Modules.
Ice Wall.
3.3 Avalanche (Fusion)
Avalanche launches a slow-moving projectile that tows enemies within its radius, grouping them for AoE follow-up. The sphere drops to the ground and only deals damage when hit by Glacial Clash, triggering Chill Explosions for a maximum of two detonations.
When you successfully trigger both explosions, Dia performs a distinctive backflip animation and recovers 300 Delight, making this a key resource management tool in extended fights.
Avalanche.
3.4 Frost Storm (Fusion)
Frost Storm is Dia’s ultimate damage ability, dealing approximately 17,000 Skill Power damage per second with near-unlimited range. It fires a Frozen Spire forward that:
- Decreases enemy Movement Speed
- Deals continuous damage within range
- Has a maximum hit count before disappearing
- Consumes 500 Delight but has a 120-second cooldown
However, Frost Storm has one major weakness: the projectile travels in a straight line only—you cannot aim it upward, downward, or sideways, forcing you to stay on the same Y-plane as bosses and enemies. This makes positioning critical during boss encounters, such as the Infernal Walker.
Frost Storm.
4. Best Builds
Dia offers two main transcendent module paths that completely shape her role:
- Chill Brand – Single-target, boss-focused build that turns her into a Chill machine gun for Colossus and elite encounters.
- Blooming Ecstasy – AoE-leaning build that makes her better at mobbing and waveclear, with wider and more reliable area damage.
In practice, Chill Brand clearly stands out as the best all-around build if you care about high-end bossing and timed clears. Blooming Ecstasy is still excellent for players who want smoother farming and more comfortable mapping, especially in places like Forbidden Sanctuary and Void Erosion Purge.
Below, we focus first on her strongest setup for bossing, then on her mobbing variant.
Dia’s build.
4.1 Chill Brand Build (Bossing / Colossus Melter)
This is your aggressive, single-target burst Dia setup for content like Infernal Walker, Wall Crasher, and high-rank Colossus missions. It leans on the Chill Brand transcendent module, high Max HP, and stacked Skill Critical Damage to convert every skill cast into a barrage of Chill-brand procs.
External Components
Prioritize a defensive shell that still feeds your passive and damage scaling:
- Max HP: Your first goal is hitting 34,616 HP to cap the 45% Skill Crit Rate from Frozen Delight.
- DEF and Max Shield: Boost survivability for melee engagements; Dia will be in the boss’s face most of the time.
- HP Recovery Modifier & Shield Recovery in Combat: Help stabilize between heavy bursts when you’re trading hits.
The best set here is Slayer for boss fights, since it heavily favors elite and Colossus damage without wasting stats on mobbing bonuses.
Slayer Set.
Trigger / Transcendent Modules
This build is centered around maximizing the uptime and impact of Chill Brand stacks:
- Chill Brand (Transcendent Module) – Core of the build; adds a 30% chance to summon a Chill Brand for 15 seconds (max 6) whenever you deal skill damage. Each Chill Brand instance then fires additional Skill Power damage every time your abilities (and Snowflake-boosted melee hits) connect.
- Ice Wall (modified) – Consumes all Chill Brand stacks to auto-attack Wedge-tracked enemies, effectively frontloading thousands of Skill Power in one button press.
- Cooldown Reduction modules – Enough to keep your Third and Fourth skills aligned with boss windows without starving Ice Wall uptime; the rest can be shifted into pure damage in this build thanks to Inversion.
- Skill Critical Hit Damage / Fusion Skill Power – Since most of Dia’s kit is Fusion and crit-based, these mods are premium for scaling Chill Brand’s output.
- Icebreaker – If you can reliably maintain Frostbite stacks on elites/Colossus, Icebreaker’s bonus damage is huge; otherwise, it can be swapped for more consistent picks.
Dia Bossing Build modules.
Weapons
Dia’s kit strongly prefers melee weapons, and one in particular stands out, the Shadow Melee Weapon. It provides Dia with:
- Multi-hit swings that trigger Snowflake’s bonus damage on every individual hit.
- Great synergy with Chill Brand, since more hits mean more procs per ability cycle.
- Keep one flex slot for Flurry or Max Impact Round to improve ammo quality-of-life.
You can play alternatives like Hypernova, but nothing matches Shadow’s multi-hit synergy with Snowflake and Chill Brand in this build.
Shadow sword.
4.2 Blooming Ecstasy Build (Mobbing / General PvE)
Blooming Ecstasy pushes Dia toward a more AoE-focused, mobbing-oriented role, trading some single-target boss efficiency for smoother mapping and waveclear.
It shines in content where enemies spawn in packs—Forbidden Sanctuary, Void Erosion Purge, and general Axion Plains farming.
External Components
For mobbing, comfort, and uptime matter more than pure boss DPS:
- Polar Night Set (4-piece) – Best in slot for mobbing thanks to high Max HP and synergy with frequent ability use.
- Stack Max HP to still hit the 34,616 HP crit cap, plus DEF, HP Recovery Modifier, and Shield Recovery in Combat so Dia feels tanky while diving packs.
Polar Night Set.
Trigger / Transcendent Modules
Blooming Ecstasy changes Dia’s skills to cover and control groups better:
- Blooming Ecstasy (Transcendent Module) – This Module transforms the Frost Storm into a lance throw that sticks to terrain and creates a large, continuous AoE zone. Holding the cast increases its range and damage by up to 200%, significantly improving mobbing potential.
- Cooldown Reduction modules – Still extremely important, so Ice Wall and Frost Storm cycle quickly and your AoE never feels “down.”
- Skill Insight + Bravery Set Option – If you move into a Bravery setup, Skill Insight replaces a second HP module to maintain 100% crit while massively improving cooldowns and spam potential.
- Steel Vanguard – Very strong for sustained AoE, as it ticks every second and helps keep Polar Night stacks active.
Dia Mobbing Build modules.
Weapons
Shadow remains excellent even in mobbing builds since Snowflake and multi-hits still do work. However, you can lean more into comfort here:
- Shadow – Still best for multi-hit Snowflake synergy and quick Chill procs.
- One flex slot for ammo QoL (Flurry or Max Impact Round) since mobbing tends to chew through resources quickly.
Shadow sword.
5. Is Dia Worth Building in The First Descendant?
Dia is absolutely worth building if you want a melee Chill Descendant who can both farm efficiently and shred bosses without swapping characters.
Dia is worth putting near the top of your project list if you match at least one of these profiles:
- You prefer melee or close‑range builds and want a Chill arche that rewards aggressive positioning.
- You regularly farm Colossus content and value fast, repeatable boss kills more than raw AFK waveclear.
- You already have basic farming covered by other Descendants and now want a dedicated single-target specialist.
- You enjoy build-crafting around HP and cooldown breakpoints, rather than simple plug‑and‑play setups.
Exposed Underwater Base run with Dia.
