Gladiolus did not immediately agree to Purple Diamond's invitation.
What Purple Diamond had said was simply too shocking. Betraying the Kingdom sounded utterly unreliable. No matter how detached Gladiolus was from worldly affairs, she could see no feasible path in it.
Besides, she was still a Flower Card magical girl with an official position. If she obediently went to the Material Realm to kill more high-rank Aberrant Beasts, or fought the Resistance Army in the Interrealm to earn some merit, then theoretically, she still had a chance of keeping her status. Though that chance was slim, it was enough for her to refuse to go crazy with Purple Diamond.
If she accepted Purple Diamond's offer and chose to betray the Kingdom, then even if she followed a Gem Scepter in doing so, the likely outcome would be a near-certain death. Neither the Garden, the Royal Court, nor the remaining four Gem Scepters would tolerate traitors within the Kingdom. The consequences would be far more severe than forced retirement.
Gladiolus valued her life dearly, because she had yet to complete her pursuit of martial arts. She did not want to gamble her life away.
But Gladiolus was also stubborn. If she retired now and lost her magic power, she would likely never be able to continue perfecting her martial arts in this lifetime.
Purple Diamond saw her conflict and hesitation, so she said, "If your reason cannot make the decision for you, then let's fight. I won't use the authority of the Gem Scepter, only my abilities as a magical girl. If you win, I will assist your research unconditionally. If I win, you come with me."
"Boss, do you really think I could win?" Gladiolus felt that Purple Diamond was joking.
"If your 'martial arts' cannot even defeat me without