The glory of armor lit the skies and the whole earth laughed,
rippling under the glitter of bronze, thunder resounding
under trampling feet of armies. And in their midst
the brilliant Achilles began to arm for battle.

– Homer

The Iliad, Book 19, lines 427-430. When Achilles steps onto the battlefield with his brilliant new shield and armor, he is clearly a changed man, the description in this passage setting him sharply apart from all the other soldiers. It speaks of the glory of his armor lighting up the skies.