4 His portance terrible, and stature tall,

portance > demeanour

5 Far passing the height of men terrestrial;

passing > surpassing

6 Like a huge giant of the Titans' race,

Titans > (The firstborn children of Heaven and Earth, as Oceanus,
Rhea, Hyperion, Cronos; see Hesiod, Theogony 132-8)

7 That made him scorn all creatures great and small, 8 And with his pride all others' power deface:

deface > cast in the shade; or: destroy

9 More fit amongst black fiends, than men to have his place.

than > [than among]