"Fuuu."
In a dimly lit apartment room, an alluring black-haired girl sat cross-legged on the ground.
White steam rose from her perfect figure as sweat dripped down her forehead. She opened her clear emerald eyes and blinked a few times.
"I did it," she said to herself.
She had managed to advance her mana core rank into the ‹Silver› stage and entered its first level – ‹Silver 1›.
Going up a level is not that difficult; however, breaking through a stage to enter the next takes a lot of time, effort, and energy.
For example, getting one's mana core from ‹Bronze 2› to ‹Bronze 3› is easier than getting it from ‹Bronze 3› to ‹Silver 1›.
To advance into the next stage, one has to forcefully compress their mana core and add layers upon layers of mana over it to create a new mana core over the already existing one.
Needless to say, the necessary process of compressing is hard and painful, and it can't be avoided.