Mechanics
Echoes and Memory Invocation
150 enemy Echoes: recruitment odds and guarantees, five roles, rank and Mastery, Memory Invocation and variants.
Recruitment
A defeated enemy can join as an Echo. The chance rises with each miss and recruitment is guaranteed after a fixed number of attempts.
| Type | Defeat number | Recruitment chance |
|---|---|---|
| Normal enemies | Defeat 1 | 5% |
| Normal enemies | Defeat 2 | 9% |
| Normal enemies | Defeat 5 | 21% |
| Normal enemies | Defeat 10 | 41% |
| Normal enemies | Defeat 15 | 100% |
| Bosses and similar | Defeat 1 | 2% |
| Bosses and similar | Defeat 2 | 5% |
| Bosses and similar | Defeat 5 | 14% |
| Bosses and similar | Defeat 10 | 29% |
| Bosses and similar | Defeat 20 | 100% |
After recruitment, defeating the same enemy can yield resonance shards for rank. This is a separate roll from recruitment, guaranteed on the 180th eligible defeat without a shard.
Five roles
Echoes are divided evenly among five roles, 30 each. Assign them to squads for the role effects below.
| Role | Effect | Count |
|---|---|---|
| Transcription | Increases passive Essence production. | 30 |
| Collation | Increases the number of Scribes produced by Editors. | 30 |
| Patrol | Shortens the time required for auto-battle and offline runs. | 30 |
| Excavation | Increases materials obtained from offline farming. | 30 |
| Deep Exploration | Increases the Binding Thread obtained in the Endless Archive. | 30 |
Rank and Mastery
Resonance shards raise rank. Ranks 2, 3, 4 and 5 require 1, 3, 6 and 11 shards in total. Dialogue unlocks at ranks 3 and 5.
After rank 5, Echoes advance into uncapped Mastery. XP required for the next level is 5 + current level × 3 (for example, 5 for Lv0→1 and 35 for Lv10→11).
Memory Invocation
- Cost
- 1 pull: 3 Memory Shards; 10 pulls: 30 (no bulk discount).
- Eligible
- Only previously recorded (encountered) Echoes. Unencountered enemies cannot appear.
- Result
- Always yields a new Echo, resonance shards or Mastery.
- Grand Resonance
- Normally 10%; guaranteed once per ten-pull cycle across single and ten pulls.
- Recruitment guarantee
- If an encountered Echo remains unrecruited, one recruitment is guaranteed per ten-pull cycle.
- Memory Focus
- Choose an area, role or favorite to assign 70% of total probability to matching candidates and 30% to others. Change or clear it free at any time.
Earn Memory Shards from ordinary enemy defeats, expeditions and permanent Memory Tasks. There is no paid gacha, paid currency or limited-time draw. The invocation screen shows the exact odds for the next pull.
Variant
Each defeated enemy has a 1 in 512 chance to yield a variant appearance for its Echo; a variant is guaranteed after 2,048 defeats without one. Recruited Echoes can also be rolled, so you can repeatedly fight a target. Memory Invocation does not roll variants. An Echo whose variant is already owned is not rolled, but its defeats still count toward the guarantee. Variants affect only appearance and the collection, not stats. There are 3 variants.
Collection stages
During the story you can collect the 36 main-story Echoes. Recording an ending expands collection through direct rematches and expeditions.
| Stage | Total | Unlock condition | Details |
|---|---|---|---|
| Foundation · Direct rematches | 60 | After the story ending | 36 main-story Echoes and 24 Elite/Apex Echoes. Can be archived through direct combat and advanced expeditions. |
| Depths · Deep realm | 78 | After the story ending and 36 successful expeditions | Record 18 Echoes across 6 deep expeditions. Action rotation and return conditions are key. |
| Alternate history · Ending realm | 96 | After the story ending and 48 successful expeditions | Record 18 Echoes across 6 alt-history expeditions and step beyond the six endings. |
| Ecology · Ecosystem realm | 120 | After the story ending and 64 successful expeditions | Archive 24 Echoes across 8 Edition-Boundary expeditions. Tailor your squad formations to match the expedition duration. |
| Relations · Relationship realm | 150 | After the story ending and 84 successful expeditions | Record 30 Echoes across 10 prime expeditions. Trace bonds with previous Echoes and see all 150 home. |
The full list is at Echo list.