Battle Mode Shift is an ability for the Exceed to be able to transform the their body figure into a larger, more muscular version for combat.
Pantherlily's Battle Form


The Battle Mode Shift ability grants the user to temporarily transform into to a larger-sized scale of oneself, gaining an increase in strength, stamina, and power. This mode, however, has been shown to be difficult to manage, as the user can usually only maintain it for a short period of time.