Bullyball

Overview

Bullyball is a multiball effect in Peglin that creates one or more balls whose damage increases when they take self-damage. It appears via several items and relics that produce additional balls (sources include Matryorbshka / Matryoshka Shell, Double Trouball, Duplication Station, Circcae, Potion Ballt, Duplicatorb, Gopher Gold and related multiball-generating effects). Bullyball functions as a specialized offensive multiball: the individual orb(s) gain strength tied to the amount of self-inflicted damage they suffer, making them scale in power as they trade HP for attack potency.

Bullyball interacts with any effect that causes the multiballs to take damage that is classified as self-damage. Damage from Rigged Bombs and from certain relics such as the Wand of Skulltimate Power counts as self-damage and will increase a Bullyball's damage. If the self-damage is negated completely, the Bullyball will not gain strength; conversely, sources differ on phrasing but all usable references agree that when self-damage occurs it increases Bullyball damage. Because the mechanic consumes the player's HP or triggers self-damage events, pairing Bullyball with reliable healing or HP-sparing effects is important for sustaining and maximizing its output.

Practical notes and strategy:

Synergies: Bullyball pairs strongly with Infernorb, Orblation, Nosforbatu, and the Wand of Skulltimate Power; these combinations increase damage or create repeated self-damage triggers that scale the Bullyball quickly.
Healing is recommended. Items such as Popping Corn, Infernal Ingot, or Nosforbatu provide healing that offsets the HP cost of powering Bullyballs; Nosforbatu additionally increases the Bullyball's damage.
Mitigating HP loss: equipment like the Gardener's Gloves reduces some of the HP lost to self-damage, letting Bullyballs grow without as much player risk.
Interactions with multiball behavior: recent updates to the game (v0.7.16, v0.7.23, v0.8.17) fixed various multiball issues—reducing escapes from the pegboard, preventing stuck multiballs on certain encounters, and stopping multiballs from continuing to trigger morbid effects after leaving the pegboard. These fixes affect Bullyball when it is produced by multiball sources and ensure more consistent behavior.
Sources and creation: Bullyballs are produced by several multiball items and relics (see listed sources above). Different multiball producers may vary in how many balls spawn and therefore how much aggregate damage Bullyball setups can deliver.