So, basically, Barbera s powers work like this: Her angry potential is like a barrel. When it overfloats - she explodes and cannot control her behavior. You can trigger the overflow at any point by infusing Barbera with Energy. this feels very good for her, so she enjoys the kicks. If Barbera is obsessively busy with something - in her case its usually books, well it was at least, that barrel gets... bigger. storing more energy, more rage without overflowing. This will never be spelled out and I completelly made this rule up. So i don t think, anybody besides myself really knows about this - that also goes for the twisted characters. The higher the Voltage, that triggers barberas sprees or the longer she hasnt had a spree before, the more excessive her explosion becomes.
