fierce attack

ONSLAUGHT
WordClue
RAIDattack
ONSETattack, storm
STORMattack, assault
ATTACKonslaught
ONRUSHonslaught
ASSAULTattack, aggression
SEIZUREvisitation, attack
INCURSIONattack
VISITATIONattack, stroke
BOMBARDMENTattack by artillery fire
SCHOLARfiend
FEROCITYfierceness