ahh, say she gets to 95-99 burst rather than 100.. happens a LOT, and since her burst ability only lasts for 3T, sometimes she doesn't double/trple atk even with rates up..
imagine being super close to raging mode in accessory quest 4 for example.. 1 more hit left for raging, then can use full burst.. shingen got 90, but the next turn runs out her 200% burst power for everyone lol. it happens so frequently. it's especially bad for those with lower grids that can't just use full burst right away and pretty much kill enemy from that.
has happened to me plenty, my friends and union mates too... always complaining bout her :P