First she tried a 'simple' magic resistance up, 'that way it'll work regardless of element'
But the magic stone they gave her couldn't withstand that, so it broke.
Then Mr. Spartan Magician shows up, give her a proper one.
She did it.
Then he start basically telling her to enchant particular effects in with the stones after that.
Poison effect reduction
Wind and Earth magic reduction
Negate poison
Negate paralysis and Water reduction
then
"Here's the last one"
Negate abnormal statuses, negate physical attacks, negate magic attacks
Sei felt becoming immune to both physical and magical attacks seem impossible to do, but raising magic resist and physical defense should work.
So she did. Oblivious to the insanity of not only 3 different enchantments, but also one of them being outright immunity.
At which point everyone else went O_O
Sei ???
The director and Mr. Spartan the let her leave without explaining much, and she get the magic resistance stone she made initially as payment.
Sei "Is this alright?"
Spartan "It's fine. You've worked enough for it"