BM
Bloodmark – Boss Melter Status Effect

Megabonk Bloodmark Guide: Effect, Unlock & Best Builds

Bloodmark stores damage on an enemy, displays it as a dark-red section of the health bar, and releases it after a short timer or immediately when the stored damage becomes lethal. This guide covers the current effect, both item sources, unlock requirements, and practical boss-focused builds.

Goal: explain Bloodmark & show winning builds
★ Reviewed July 27, 2026 · Current through v1.0.69
✓
Bloodmark TL;DR – what does it do?

Bloodmark stores separate damage on the target. The dark-red portion of a boss health bar shows how much damage is waiting to resolve; it is not a percentage-based max-HP reduction.

A hit-based mark normally resolves after 5 seconds; a lifesteal-applied mark uses 4 seconds. Applying another stack refreshes that mark's timer. If stored Bloodmark damage is already enough to kill the target, it resolves immediately.

Use Unstable Transfusion for a 35% on-hit chance. Bloody Cleaver adds another 50% on-hit source and converts Lifesteal into Bloodmark stacks. Damage, player level, hit frequency and stack count matter; Bloodmark cannot crit and does not heal you.

Core mechanic

What is Bloodmark in Megabonk?

Bloodmark is an enemy debuff that accumulates pending damage. On bosses, that pending amount appears as a dark-red section of the health bar.

When the mark's timer ends, the stored damage is dealt. If the stored amount reaches or exceeds the enemy's remaining HP first, Bloodmark resolves immediately and kills the target. That lethal check is why it often looks like an execution.

  • It is not a fixed percentage of enemy maximum HP. The visible section represents stored Bloodmark damage.
  • It does not provide healing. Bloody Cleaver can create stacks from Lifesteal, but Bloodmark itself is damage.
  • It cannot crit. Damage scaling is useful; Precision is not a direct Bloodmark multiplier.
  • It is most noticeable on bosses because fast regular enemies often die before the delayed mark matters.
Under the hood

How Bloodmark Works: Stacks, Timer & Damage

Every successful application adds a stack to the target. More stacks increase the pending damage, while a new application refreshes the active mark timer.

1. Apply stacks

  • Unstable Transfusion: currently 35% chance to apply Bloodmark on hit.
  • Bloody Cleaver: adds 50% chance to apply Bloodmark and makes Lifesteal add Bloodmark stacks.
  • Chances above 100% can produce guaranteed stacks plus a chance for an additional stack, so duplicate items remain useful.

2. Wait for the trigger – or reach lethal damage

  • Marks applied by normal hits use a 5-second base timer.
  • Marks created through Bloody Cleaver's Lifesteal interaction use a 4-second base timer.
  • Reapplying Bloodmark refreshes the timer. If pending damage becomes lethal, it resolves immediately instead of waiting.
Current tested formula

Damage per resolved mark

(Player Level + 8) × 0.75 × Damage Multiplier × Bloodmark Stacks

  • Damage Tome helps because Bloodmark uses the Damage multiplier.
  • Cooldown and Quantity help indirectly when they create more qualifying hits.
  • Crit Chance and Crit Damage do not multiply Bloodmark; the mark itself cannot crit.
  • Duration changes the timer, not the damage stored per stack.

Why it looks like an execute: when the dark-red pending-damage section reaches the boss's remaining health, Bloodmark fires immediately. Large stacks can therefore end a boss phase before ordinary damage reaches zero.

Unlock & sources

How to Get Bloodmark: Items & Unlock Paths

Bloodmark is not a standalone unlock or character passive. You gain access to it through two items.

Unstable Transfusion Available by default

Current effect: each hit has a 35% chance to apply Bloodmark. This was increased from 27% in v1.0.49.

  • Unlock: none; it is in the item pool by default.
  • Best with: reliable, frequent hits and Damage scaling.
  • Does not need Lifesteal: the on-hit effect works on its own.

Open the Unstable Transfusion item guide →

Bloody Cleaver Vlad unlock

Current effect: Lifesteal adds Bloodmark stacks, and the item also supplies a 50% on-hit chance to apply Bloodmark.

  • Unlock: reach Level 50 as Vlad.
  • Best with: Vlad, Lifesteal and weapons that maintain frequent damage contact.
  • Works without Transfusion: it is a separate Bloodmark source, though both items stack well together.

Open the Bloody Cleaver item guide →

Unlock order: you can use Bloodmark immediately whenever Unstable Transfusion appears. Bloody Cleaver becomes an additional permanent item-pool option after completing Vlad's Level 50 requirement.

Practical builds

Best Bloodmark Builds & Playstyles

Bloodmark isn’t a full build archetype by itself – it’s a win-condition layer you bolt onto strong characters. Below are three practical setups you can actually run, each linking out to deeper build guides on Megabonk.org.

Vlad Lifesteal Bloodmark Execute
Boss melter
Character: Vlad Weapons: Aura / Katana / Lightning Staff

Stack lifesteal and on-hit effects so Vlad can stand inside packs, feed Bloody Cleaver and Transfusion, and watch bosses explode as soon as they spawn.

  • Core items: Unstable Transfusion, Bloody Cleaver, lifesteal pieces.
  • When to play: high curse, leaderboard pushing, long boss waves.
View full Vlad Bloodmark build guide →
Fox & Aura: Fast-Hit Bloodmark Spam
Beginner friendly
Character: Fox (Kitsune) Weapons: Aura / Tornado / Mines

Lean into Fox’s high luck and pick up Transfusion with rapid multi-hit weapons. You’ll mark everything on screen while still having smooth wave clear.

  • Core items: Unstable Transfusion, Damage scaling, plus Cooldown or Quantity where the weapon benefits.
  • When to play: early Bloodmark learning, all-round runs that still care about bosses.
View Fox best build (Bloodmark variant) →
Megachad / Ninja High-Speed Marking
Speed-clear hybrid
Characters: Megachad, Ninja Weapons: Katana / Hero Sword / Space Noodle

These characters can maintain frequent close-range hits. Adding Bloodmark lets them turn already strong clear into much faster boss kills.

  • Core items: Unstable Transfusion + generic melee scalers.
  • When to play: if you naturally find Transfusion mid-run on a high-DPS build.
See Ninja best build ideas →

Want to browse more setups? Check the general build hub: Megabonk best builds overview →

Decision making

When to Take Bloodmark – And When to Skip It

Bloodmark is powerful, but not automatically correct in every build. Treat it like a “boss phase delete” button: amazing when that’s what you need, skippable when it’s overkill.

Recommended: situations where Bloodmark shines

  • High curse / high difficulty runs where boss HP is high and fights drag if you don’t have a finisher.
  • Leaderboard attempts where shaving seconds off every boss directly improves your score.
  • Builds with many hits per second (Aura, Katana, Lightning Staff, Tornado, Space Noodle, Mines).
  • Characters who already want lifesteal and melee uptime (Vlad and similar bruisers).

Borderline: “nice to have” but optional

  • Wave-clear builds that already delete elites and bosses in seconds without help.
  • Runs where you are starved for defensive items and can’t afford to give up survivability.

Quick rule of thumb

  • If bosses feel tanky or fights feel long → take Bloodmark.
  • If everything already melts and you die to random hits → prioritize defense first.
  • If you’re not hitting often (slow sniper / single-shot builds) → value is much lower.

In other words: Bloodmark needs reliable applications and Damage scaling. A slow build can still use it, but frequent hits create more chances to add stacks.

Patch status

Bloodmark Version Changes

v1.0.49 · December 25, 2025

Unstable Transfusion's Bloodmark chance increased from 27% to 35%. All recommendations on this page use the current 35% value.

Checked through v1.0.69

No later official Bloodmark-specific balance change replaces the v1.0.49 Transfusion value. Bloody Cleaver remains the Level 50 Vlad unlock and 50% on-hit/Lifesteal source.

Common questions

Megabonk Bloodmark FAQ

What does Bloodmark do in Megabonk?
Bloodmark stores pending damage on an enemy. It normally deals that damage when its timer ends, but resolves immediately if the stored amount is enough to kill the target. The dark-red health-bar section shows the pending amount.
Is Bloodmark a percentage of enemy max HP?
No. It is damage calculated from player level, Damage multiplier and Bloodmark stacks. A boss can appear to lose a large percentage because many stacks have accumulated, not because Bloodmark automatically scales from that boss's maximum HP.
How long does Bloodmark take to trigger?
A mark applied by a normal hit uses a 5-second base timer; a mark created through Bloody Cleaver's Lifesteal interaction uses 4 seconds. Reapplying the mark refreshes the timer, while lethal pending damage triggers immediately.
How do I unlock Bloodmark?
Unstable Transfusion is available by default and currently has a 35% on-hit Bloodmark chance. Bloody Cleaver is unlocked by reaching Level 50 as Vlad; it adds a 50% on-hit chance and converts Lifesteal into Bloodmark stacks.
Can Bloodmark crit or heal me?
No. Bloodmark damage cannot crit, and Bloodmark itself does not heal. Bloody Cleaver uses Lifesteal as a source of stacks, but the healing comes from Lifesteal, not from Bloodmark.
What stats are best for a Bloodmark build?
Prioritize Damage, then use Cooldown, Quantity or other weapon-appropriate stats to create more hits. Precision is not a direct Bloodmark scaler because the mark cannot crit.