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Hollow Knight Silksong Act 4 Walkthrough

Prepare Hornet for Pharloom's summit with detailed routing, puzzle solutions, boss tactics, and collectible tracking. This Act 4 walkthrough bridges Act 3's Radiant Archives to the Act 5 finale, ensuring you secure every upgrade before the point of no return.

Region Overview

Pharloom Summit, Radiant Archives, Celestial Elevator

Key Boss

Radiant Regent (multi-phase aerial encounter)

Estimated Length

60–90 minutes with full collectible sweep

Preparation Checklist

Core Upgrades

  • Silk Dash Lv3
  • Silk Spool Lv3
  • Shell Fragments Lv4
  • Stormguard Charm

Recommended Builds

  • Aerial Burst (Silk Bind + Stormguard) for clone suppression
  • Sustain Route (Silk Heal Lv4 + Thorned Cloak) for radiant zones
  • Aggro Route (Needle Lv4 + Echo Chamber charm) for speed clears

Support Tools

  • Interactive Map markers for Radiant Archives
  • Boss Tracker entry for Radiant Regent
  • Endgame Checklist (Act 4 section) for collectibles

Summit Approach & Required Tools

Ensure Hornet is equipped with Silk Dash Lv3, Thorned Cloak, and at least Silk Spool Lv3 before entering the summit region.

Key Checkpoints

  • Unlock the Celestial Elevator using three Radiant Keys from Act 3 side quests.
  • Activate the Respite Chamber bench to bind your respawn near the summit entrance.
  • Collect the Resonant Bell to open spectral gates later in the act.

Strategy Tips

  • Bring ranged silk abilities to clear aerial sentries without committing to melee trades.
  • Keep one charm slot free for situational swaps (Stormguard vs. retaliation charms).
  • Mark map pins for silk geysers leading back to the summit camp for quick refills.

Radiant Archives Puzzle Route

Solve memory prism puzzles to align the summit's light bridges and unlock the boss arena.

Key Checkpoints

  • Align the first prism in the eastern wing to illuminate the central elevator.
  • Eliminate three archive wardens guarding glyph tablets containing bridge patterns.
  • Collect the Echo Chamber charm to reduce incoming radiant damage by 20%.

Strategy Tips

  • Use Silk Bind to tether sentries away from puzzle consoles during alignment sequences.
  • Focus on ranged sentries first—melee units despawn once prisms align correctly.
  • If you fail a prism, reset via the control core on the lower deck to avoid enemy respawns.

Boss: Radiant Regent Encounter

Three-phase duel emphasizing aerial control, radiant bursts, and summon management.

Key Checkpoints

  • Phase 1 introduces radiant mines—destroy them with ranged silk before they detonate.
  • Phase 2 shield rotation requires countering after parry windows; watch for triple dash telegraphs.
  • Phase 3 adds spectral clones—use Thorned Cloak to punish overlapping dive attacks.

Strategy Tips

  • Equip Stormguard Charm to reduce stagger from radiant blasts.
  • Maintain mid-air positioning; downward strikes cancel the Regent's hover beam.
  • During clone phase, focus on the clone with brighter aura—the real Regent follows its path.

Act 4 Collectibles Checklist

Track every silk capsule, lore tablet, and rare item before leaving the summit.

Key Checkpoints

  • 5 Silk Capsules hidden behind radiant gates—use the Resonant Bell to open them.
  • 2 Lore Tablets documenting Pharloom's founding—scan them for Hunter Journal entries.
  • 1 Radiant Core required to access the endgame path in Act 5.

Strategy Tips

  • Use the Interactive Map tool to mark found capsules and tablets in real time.
  • Combine the Echo Chamber charm with Silk Heal Lv4 to endure radiation zones.
  • Return to summit camp to bank geo before progressing toward Act 5 triggers.

Route Resources & Next Steps

Interactive Map – Summit Layer

Toggle the Act 4 layer to visualize radiant gates, silk capsules, and elevator paths.

Boss Tracker – Radiant Regent

Log attempts, best times, and reward drops to optimize the summit encounter.

Endgame Checklist

Ensure every Act 4 collectible is secured before Act 5 triggers.

Charm Builds for Summit

Equip optimized charm sets tailored for Radiant Regent and radiant zones.

Continue to Act 5 Walkthrough (Coming Soon)