again > in return

2 With so fierce fury and great puissance

so > such puissance > force

3 That through his three-square scutcheon piercing quite,

three-square > equilaterally triangular scutcheon > escutcheon, shield

4 And through his mailed hauberk, by mischance

hauberk > {Military tunic, usu. of chain-mail}

5 The wicked steel through his left side did glance;

glance > dart, shoot (esp. obliquely)

6 Him, so transfixed, she before her bore