Stella was wandering the canyon for weeks looking for an exit, whilst trying several unsuccessful methods to strengthen her spiritual power. She did not remember or know how u do it, instead she fell back on physical exercise as a soul. She noticed that the remains of her chain of fate was slowly dissolving.
"From the rate of decay, it would probably take me around one more month to hollowfy, I wonder what I'll look like as a hollow, bit sad but no Shinigami has even bothered to look for my soul, is it because I died away from civilization in the middle of nowhere ? Maybe they're lacking the technology to find me. Since Urahara should not be a captain yet at least I think so. The timeline is a bit blurry for me to remember the exact dates."
During the next month of isolation that stella was experiencing seemingly took a bit of a toll on stella's mind as she already accepted her future as a hollow, she began to think about what the best places would be to grow stronger.
"The last piece of my chain still remains, I wonder how much longer I can hold on, the lingering pain is getting stronger and stronger every day,"
Stella continued to wander the canyon until the last remaining piece of her chain of fate started corroding when she felt an immense pain, as if her entire body was bei9ng torn apart. She instantly collapsed on the floor struggling to breathe. She desperately wailed her arms at the last remnant of chain that was causing her all of this pain.
"URHGHHHSHGHSH!!! AUGRHHRG AHHHH RUAAGAH ARGHH URARRH"
Stella let out many anguished screams that were slowly transforming into beastly howls as she continued to claw at the eroding chain, her body started to spasm as a white substance started leaking out from all of her orifices that slowly started to form a kind of cocoon around her.
Over the next few seconds, the cocoon completely formed only to then crack apart revealing a small red and white spider shaped hollow with a hole in between its chest.
Stella's Mind at this point was reduced by many magnitudes barely holding onto her human identity driven mostly by instinct she barely formed coherent thoughts.
"Must… Escape… Feed… Souls… Food."
Instinctively she opened a garganta and escaped to Hueco Mundo.
Now Stella was in Hueco Mundo, a dimension filled with hollows between the world of the living and the soul society. These Hollows are born from deceased human souls that lose their heart, are in despair or wander aimlessly with regrets.
Stella now a little spider hollow was wandering the empty planes of Hueco Mundo and stumbled into another newborn hollow.
'Soul Feed Eat Hollow EAT!'
Upon spotting this hollow before her, she went into a kind of frenzy eagerly wanting to devour the hollow before her.
Her 8 Legs quickly sprinted at this tiny rabbit shaped hollow that did not seem to notice her and jumped at it. Stella used her fangs and bit into the Rabbit hollows mask and began to bite it off piece by piece until the hollow collapsed and died.
Eagerly Stella consumed the hollow and completely devoured it. The moment she finished slightly more complicated thoughts began forming in her mind.
"No Food Wrong, Me Stella, Food Good."
Afterwards she began to wander Hueco Mundo again.
Like this a few weeks passed where stella began hunting down the hollows around her trying to ambush them by staying low to the ground and jumping at them from above. So far, she has consumed hundreds of Different hollows of similar or weaker strength to herself consuming a thousands of Souls in total This increase in spiritual power, lead to her fragmented mind to slowly get back together, but she was still dominated by her hollow instincts...
"Need to look for more Food, me am starving, I'm hungry, where… I need more prey, stella hungry."
At this Point Stella's Body grew to several Meters dwarfing her initial size when she arrived in Hueco Mundo. She went from newborn hollow to a large hollow.
She even gained a unique special ability that allowed her to copy one ability of any hollow she devoured. The Special Trait she decided to stick with so far was a kind of soul venom she gained from a centipede shaped hollow.
With her Venom, her hunting strategy was rather simple, try to lay low and ambush any hollow jump on them bite them, then jump off and wait far away until they collapse and finish them off. Her Mind.
This simple process of Murder continued for months until the number of souls she consumed reached thousands. It was at this moment Stella collapsed.