How players use it
- Rainbow cards by job Single-target boosts: Gigantify doubles size, damage and HP; Balance sets HP and damage to the higher of the two; Accumulator (1.0) grows by 9% for each year you hold it; Precision +100% first-hit damage per stack.
How to get it
- Loot after beating the Jack of Rainbows (twice per run).
- Merchants have a chance to stock one; the Lucky perk and Rare Goods decree raise it.
- Gacha at max level, Diffract and the Refraction decree give random Rainbow cards.
Other Jack of Rainbows tomes
Achievements
- Big Guy: Gigantify a single troop 3 times in a run.
Data: 9 Kings 1.0 card table on the official wiki, imported 2026-11-13.