The Armor, Heart of the Praxic Fire, has references to the Dark Souls character Solaire of Astora:
One of the upgrades is titled "PRAISE THE SUN". The upgrade's icon also resembles the emote of the same phrase.
The description, "In that last moment she seemed as wholly luminescent as the Sun, and I wished to be so brave." is likely a reference to Solaire's line, "The Sun is a wondrous body like a magnificent father. If only I could be could so grossly incandescent."