FFX riddles

[Hazzard]

sorry BG, but i couldn't be bothered walking

repost:

In ancient times over land and sea,
A group of people worshipped me;
Many feared, many did repent
I was given the name Slayer of Serpents

In a more spirited time, I've lost my light
My prowess, my speed, and even my fight
Flames and bolts will pierce right through
Before I can even attack you.

hints:
- the first stanza doesn't refer to ffx
- it is a monster

still have no idea tho

First of all, I can't even work out the highlighted line, and second of all; the highlighted word was a Typo.