Ruby : Brimstone

Take Ruby, add horns, and let the ground burn: that is the idea of Ruby : Brimstone. The Sol's RNG Wiki describes a red-themed aura with a big red star at the top and a smaller one nearby, rocks of different sizes circling the player and slowly vanishing, red whirlpool-like particles that spin around them, and a red floor that gives off burning particles. The player also gets two unique accessories, a pair of horns and a symbol, referencing Ruby.

It was added in Eon 1-17, the Boss Raid Chapter 2 update, as an Exalted aura with a base chance of 1 in 24,000,000. That is about 24,000,000 rolls at 1x luck, or 2,400,000 at 10x, a long way above the 1 in 350 of the Basic Ruby. No biome or event is attached. The in-game description is still Ruby's, a gem of a red hue, which makes the contrast between the text and the fiery visuals even larger. The music is Left Alone by DM DOKURO, and SevenSpacess is the credited creator.