Thanks you for your advice. Blood Moon seems like fun, too, but I'd rather be blue based. Standstill looks fine. Therefore I'd make the following exchanges:
3x Standstill for 3x Preordain
3x Tundra + 4x Mishra's Factory + 2x Islands for 7x Islands + 1x Plains + 1x Tundra
3x Wasteland for 2x Back to Basics + 1x Thing in the Ice
1x Crucible of Worlds for 1x Jace, Vryns Prodigy
2x Stony Silence for 2x Null Rod
Maybe take out Mystical Tutor or Merchant Scroll for another Swords.
Maybe add Narset Transcendent, I really like her.

I love long games, but my biggest threat is the time on magic online. Guess I need to train a bit more 🙂

Thanks guys and best regards,