A witch's class change was similar to multiclassing in the Dungeons & Dragons system—or rather, it simply was multiclassing. Yet for various reasons, Jiang Han had to distinguish the two.
Their class-change system resembled "advancement."
By raising the grade of one's life, one gained an entirely new spellcasting system. Jiang Han's psionics, for instance, counted as a "minor advancement," but unless she transformed into a psionic witch, it would be difficult for her to gain an advancement along that path.
In more data-oriented terms, changing class also meant new "Hit Dice," new "Will Dice," and so on, along with a whole set of sorcerer class levels.
(Witches leaned toward mages, but they could also be described as mage-leaning sorcerers.)
However, witches did not have the DnD system's experience pool—that is, there was no XP setting. Every class change meant that the main body's experience was diverted. Once that experience was diverted, a witch would receive the following debuffs:
"Reduced mana ratio during the growth period," "all-around ability weakening," "thought-process penalties," "reduced mana control rate," and so on.
The reason Angelite was said to have set a bad example was that if an ordinary witch copied Angelite and changed classes ten or twenty times, she might spend her entire life barely learning the most basic specialty abilities. She might even become one of the legendary "single-threaded witches," or a "stupid witch."
It was precisely because class changes required caution upon caution—like playing a "Minecraft with mods you couldn't uninstall"—that many powerful witches had yet to choose a class change.
The most famous example was probably the great Lilith Dragon Plush. Miss Dragon Plush had never changed classes.
Of course, the time was drawing near.
That was because the more formidable witches generally developed a class of their own and DIYed it