Perfected Reactant

Perfected Reactant is a relic that increases the damage of bombs. It functions as an upgraded form of the Improved Catalyst, providing a flat additive bonus to any bomb damage the player deals.

The relic's in-game effect is described as increasing bomb damage by a specific value (Additional Bomb Damage). The current numeric value has changed across versions: it was introduced in the Beta, appeared in Early Access, and later adjustments changed its magnitude several times. In v0.7.42 the damage was reduced to 15 (from 20), and in v1.0.6 the damage buff was increased back to 20. The item also underwent a bomb icon change at an unknown update.

Practical notes and interactions:

• The bonus is additive to each bomb hit; it directly increases the damage shown for bomb effects.
• Stacking with other sources of bomb damage or general damage modifiers follows normal game arithmetic: the Perfected Reactant adds its flat bonus before multiplicative modifiers apply.
• Because the relic boosts bombs specifically, it is most valuable in runs that rely on bomb-generating cards, enemy bombs, or relics and modifiers that convert effects into bomb damage.
• It is functionally the elevated version of Improved Catalyst; players should treat it as a focused damage amplifier rather than a broad damage relic.

The name implies it is the "perfected" variant of the Improved Catalyst; the exact in-game method to obtain or "perfect" the item is not documented in available sources.