253) No one is autorized to summon Core Drills to try to resolve the problems of the Magical World.
And here are the steps of Haruna's plans to become a Magical Girl with access to a Deus Ex Machina of incomparable power aka The Ginzuishou.
1) Check if the Silver Millennium does indeed exist into the Libraly Island. If yes, go to Step 2. If not, search/summon something different (see 253 for an example).
2) Steal the Cassiopea.
3) Overpower it with a Plot Device/Deus Ex Charge to go into the Silver Millennium, during its Fall.
4) Interfer with a SEP (Someone-Else-Problem) Spell with the reincarnation spell.
4a) Make sure to be the future reincarnation or, to avoid paradoxes, make sure the future reincarnation of Princess Serenity/Sailor Moon is one of your classmates.
5) Try to avoid the karmic backfire that will make you become BERYL's reincarnation.
6) Return to your own time.
7) ???
8) PROFIT!!!