Vampire Survivors Heart of Fire Guide: Unlock and Explosion Builds

The short answer: reach level 50 with Arca

Heart of Fire (XIX) is unlocked by reaching level 50 with Arca. Projectiles from listed weapons explode on impact, light sources explode when destroyed, and the character creates an explosion when damaged.

It supports fire and explosion-focused area damage, but it does not make every weapon explosive.

Unlock steps

1. Make Arca available.
2. Start any stage with Arca.
3. Reach level 50 during the run.
4. After the run, confirm that Heart of Fire (XIX) is unlocked.

Current official Steam achievements use level 50, not the older level 99 condition.

Reading the effect

• Projectiles from listed weapons explode when they hit an enemy.
• Destroyed light sources also explode.
• Taking damage creates a retaliatory explosion around the character.
• The supported weapon list can expand with updates, so check the in-game card text.

The retaliation is not damage prevention. On harder runs, pair it with enough Armor, healing, or movement to survive the hit.

Read next

• Divine Bloodline (IX)
• Weapon evolution basics
• Arcana unlock list

Sources

• Official Vampire Survivors Wiki: Heart of Fire
• Official Steam achievements