Bloomreaper the Invincible is Borderlands 4’s first raid boss, added December 11, 2025 in a free content update alongside Ultimate Vault Hunter Mode Rank 6. It remains the raid route to learn before moving into Raid Boss 2: Subjugator and Thol and the UVHM 7 unlock path. We are an unofficial fan site; this guide is sourced from official notes and community boss guides (MentalMars) and rechecked against the Version 1.8 baseline.

Type: Raid boss
Region: The Bloom, Carcadia Burn
Requirement: Level 50+ endgame build, UVH Rank 6+
Farmable: Yes, repeat the encounter for the loot pool

Quick answer

  • Unlock: finish the campaign, pick up The Wrath of Bloomreaper from a Bounty Board, then travel to the Lowrise Safehouse route in Carcadia Burn.
  • Main mechanic: destroy Vile Crystals, survive thorn / laser pressure, then clear the fog phase.
  • Main farm target: Rainmaker is the headline reward; Mantra is the searchable shotgun drop from the same raid pool.
  • Next step: compare the loot in the weapon database before committing a full farm session.

How to unlock Bloomreaper

After finishing the main campaign, pick up the side mission “The Wrath of Bloomreaper” from a Bounty Board in a Faction HUB town. To reach the arena, fast-travel to the Lowrise Safehouse in the Tonnage Peel province of Carcadia Burn and head south toward the Bloom. Bring an optimized skill tree and your strongest weapons — this is tuned for endgame builds.

The three phases

  1. Crystals. Destroy the Vile Crystals surrounding Bloomreaper and clear the Vile Wisps it spawns.
  2. Thorns and lasers. Move across the platforms while dodging laser attacks and thorns.
  3. Fog. A final immunity phase in heavy fog — survive it to open the kill window.

Loot pool

Bloomreaper drops a pool of 9 legendaries. Weapon drops are 15% (+2% per UVH Rank), with one guarantee:

  • Rainmaker — Ripper sniper, guaranteed at Platinum tier on first clear
  • Mantra — Maliwan shotgun
  • Jetsetter — Ripper heavy weapon (ordnance)
  • Urchin — Tediore grenade mod
  • Undershield — Vladof shield
  • Class mods — Lamplighter (Amon), Trooper (Harlowe), Overdriver (Rafa), Misericorde (Vex)

Element and card stats scale with your level and roll, so verify them on your own drop.