Here is the full list of all 40 METALLIC CHILD achievements.
Collect all Fan-art.
Defeat the Metallic Child, Magna.
Defeat all Metallic Childs.
Clear Terminal Creed.
Defeat the Metallic Child, Spyden.
Help deliver Trevon's virus case 20 times.
Defeat the Metallic Child, Icela.
Defeat 3000 enemies.
Defeat the Metallic Child, Gigantic.
Defeat the Metallic Child, Flyer.
Repair Schrodinger 20 times.
Rescue 20 survivors.
Defeat the Metallic Child, Lighton.
Accomplish 30 combos.
Open Daviny's box 20 times.
Defeat the Metallic Child, Faceless.
Help retrieve Sly's weapons 20 times.
Accomplish = double kills.
Be graded an S for battle 100 times.
Defeat the Metallic Child, Controd.
Deal 600 damage or more to an enemy in a single hit.
Install 150 Mini-cores.
Defeat the Metallic Child, Shutty.
Defeat the Metallic Child, Graver.
Experience a defeat in battle.
Visit the various facilities of Life Stream.
Defeat the Metallic Child, Fira.
Install 200 bugged and viral Cores.
Install 150 Super-cores.
Clear all Virtual Missions.
Accomplish 100 triple kills.
Accomplish 30 fantastic kills.
Perform 200 Chain-skill attacks.
Go on camera 20 times, for Miamo's live stream.
Defeat 20 of Catherine's modified robots.
Be graded a D for battle 100 times.
Collect all Recor-Ds.
Change weapons 100 times during battle.
Equip a drone 100 times during battle.
Perform 200 Take-downs.