Source: Bestiary 3, pg(s). 37
Tempest behemoths can fly with their three pairs of wings, giving them better mobility than other behemoths. In battle, they drop on foes from great heights, smash them with wing buffets, or fire razor-sharp scales or lightning bolts at them. Due to their divine protection, tempest behemoths are serene in their immortality and fear no other being. Few worlds are capable of the level of blasphemy and hubris that would necessitate multiple tempest behemoths as divine punishment.
Foul weather and terrific storms that drive flocks of birds before their headwinds precede the arrival of a tempest behemoth. The day before the arrival, the storms suddenly abate, ironically encouraging victims to emerge into the open just as the behemoth strikes.