My Phone Can Break Through Dimensions

[Jujutsu Kaisen + Genshin Impact] (Includes some other anime, but they won't affect your reading experience.) After transmigrating to another world, Sanyue became the young lady of the Ragnvindr family. She had a phone that could cross dimensions, and her everyday routine involved gaming with her online friends. As she grew stronger and stronger, she gained the ability to travel between worlds...

She trains up in the early part of the story, then summons her friends from Teyvat to fight Sukuna later on.