Star Guardians made such lovely decorations inside bacterium pods. The bright green jelly that preserved them in a loose definition of alive made their costumes sparkle like diamonds and their hair twinkle like comet dust. Their imprisoned silhouettes were easy to spot in the translucent membranes that plagued the Thoughtreaper's body.
A Thoughtreaper Sentinel was comprised mostly of tentacles and pustules. They were capable of harvesting any intelligent being who was unlucky enough to be absorbed into one of the pustules, but they were the most content when they got to act as guard breakers. This particular Thoughtreaper had sprouted enough man-eating germ pods to contain a small army of mortals, but he only needed to worry about eight Star Guardians. There was more than enough room to complete the whole set.
The Guardians' battle against a raid boss had ended with them becoming produce lining the sides of a giant slime-infested fruit basket.
Syndra was the first one to make her new home in the bacterial soup. The other Guardians fell in battle and were given their own pods soon enough. Ahri was the last one to be captured, the tricky fox. And by the time she was finally contained, she had seen plenty of what was becoming of her allies. It was just easier to process the meat in bulk.
Once their feeblish struggling stopped and their minds succumbed to the effects of stasis magic, the Star Guardians' pods were covered by throbbing flesh curtains. Their pods glowed only dimly underneath as they were secretly disenchanted and broken down into their most principle elements. They never felt the slightest hint of pain in their sleep, as their minds were kept senselessly adrift in the borders of an alien dimension. Bad dreams slipping through emerald clouds.
The curtains peeled away, revealing all that was left of each Star Guardian was her brain and the first couple inches of spinal cord. Lux was a brain. Syndra was a brain. Jinx was a brain. Sona was a brain. Miss Fortune was a brain. Janna was a brain. Katarina was a brain. Ahri was a brain with her nerve endings waving around in the jelly like a drunken set of fox tails. Lightning filled the bright green pods and charged through the helpless brain matter, teaching the pickled Guardians what the name "Thoughtreaper" really meant.
Star Guardian lore would paint this day as a sad fairytale telling of how the Guardians' bodies were destroyed in the final battle against the Thoughtreapers and their minds became corrupted into cosmic horrors. Thoughtreaper lore would mostly consist of technical details on how the little Rift rats were cleansed and reborn in their true forms.
The pods began frothing in green bubbles. It only took a few seconds to synthesize new husks for the Guardians and encase their minds in Thoughtreaper form. They were made solid from astral minerals that perfectly matched the shapes and proportions of their original organic blueprints. They were animated by the same magic principles that brought a stone golem to life.
These creations of synthesis were bound in formfitting suits that were mostly black and silver and trimmed with their brighter Guardian colors. They were fitted with sleek crystal helms that completely covered the top halves of their faces and heavily shielded their brains—the most vital organs they had left. Antennas poked up from the sides of the helmets like large padded ears. Thoughtreaped Sona looked the most natural in her new form, but the others were still gems by comparison.
The bacterium pustules burst open like eight human-sized potion flasks. The Thoughtreaped crawled up from the waves of green ooze, fully awakened and ready to conduct the world into its annihilation.
Author's note: This isn't Neverwinter and these Thoughtreaper fellas are totally not the same thing as Mind Flayers. I have no idea what you're talking about.