Bubos reduces boss HP. The HP reduction of bosses goes toward an HP 5 times the health of a non-boss monster, and is a logarithmic growth.
Bubos's summon cost is the player's current summon cost.
Bubos's cost per level is 2n, with n being equal to the next level.
All costs except the summon cost can be reduced by Chor'gorloth.
The bosses' HP reduction follows the equation:
HP reduction of bosses = -5×(1-e^-0.002n)×Effect of K'Ariqua
The table below shows the effect of Bubos at certain levels.
- Bubos, Ancient of Diseases, is a reference to the Bubonic plague.
- Prior to patch 0.14, there was a bug that caused Bubos to give double his described effect.
- This ancient has the slowest convergence among the ancients whose effect converges, ( Atman, Bubos, Chronos, Dogcog, Dora, Fortuna, Kumawakamaru, Revolc, and Vaagur), along with Dora. Both effectively max out at level 18715.
- Along with Vaagur, this is the only ancient to have a mouth. Morgulis does not count as only the top part of its mouth is visible.