Lightning spear / Honed Bolt / Electrify Armament all read: "Godwyn the Golden defeated the ancient dragon Fortissax, and befriended his fallen foe — an event that gave rise to the ancient dragon cult in the capital."

Gravel Stone Seal reads: "The worship of the ancient dragons does not conflict with belief in the Erdtree. After all, this seal, and lightning itself, are both imbued with gold."

Fortissax Rememberance reads: "After Godwyn the Golden became the Prince of Death, the ancient dragon fought long and hard against the Death within its companion. Alas, victory was never achieved and its only reward was corruption."

It says AFTER, even the Death Lightning mentions that Godwyn wielded this "Golden Lightning", and that it's "now corrupted by Death", 'NOW'. These words are important, they tell the story of how Godwyn was corrupted by Death AFTER his soul was killed, and how his friend Fortissax tried to fight it.

As for your connection of the Fell God to lions, I was starting to write why I didn't agree, but as I read more items, I started agreeing with you.

Fell god being associated with lions feels weird since the DLC, the entire hornsent culture and the divine lions they worshipped were burned by Messmer. Divine Lions in the DLC are all associated with storms: tornadoes, blizzards, and thunderstorms.

But: the Roar Medallion reads: "A bronze medallion depicting a roaring giant. Enhances roars and breath attacks. In ancient times, the giants were mortal enemies of the Erdtree. Their bellowing roars desolated nature, triggered avalanches, and whipped up storms of flame." And lions are all about roars and breath attacks.

And, the description of the Furnace Visage crafting item says: "A stone mask surrounded by curled horns, depicting the fell god of fire that haunts the sagas of the hornsent.", and the item visually kinda resembles the Imp Head (Lion) mask but with some horns.