en_tn_condensed/job/41/15.md

shields

The word "shields" is a metaphor for Leviathan's hide. Both shields and Leviathan's hide protect well and deflect arrows and other weapons. (See: rc://en/ta/man/jit/figs-metaphor)

tight together as with a close seal

This means the "shields" are very close to one another and nothing can get between them.