Fierce is the adjective used to identify the individual or group entering battle, attacking insurmountable odds or challenges.
Wars have produced fierce, violent attackers eager to fight or kill.
When not being used to describe wars or battles, the adjective is applied to persons in a sporting event.
The fierce golfer, of a final round to win a tournament handles the pressure to win.
The pitcher who throws a no-hitter is described as a fierce attacker to strikeout the final batter.
The adjective has been used to describe the mother who prepares a 7-course Thanksgiving dinner including dessert within ten hours for a family of five with attention to detail without any assistance is described as fiercely attacking the kitchen to fed her family.
And then there is me after the Thanksgiving blessing is finished, I fiercely attack my plate of food consuming everything to get to the dessert.