I'm the Evil Lord of the Honkai World!

Meet Liam Sera Banfield-formerly an ordinary human, now a dimension-hopping, music-loving contractor for a shadowy omniversal company. Armed with the Catalog, a mysterious system that grants him incredible powers (after some intense training, of course), and a penchant for causing chaos with a smile, Liam's latest adventure drops him right into the midst of Herta's Space Station in the Honkai universe.

The station gets invaded by the formidable Antimatter Legion. But don't worry-Liam's got this. Maybe. Sort of. Okay, not really. But that won't stop him from cranking up AC/DC's "Back in Black" and dancing through the danger with his trusty sidekick, Mysterious Heroine X, who insists she's a Saber (but we all know the truth).

--------

Waifu Catalog Inspired Fanfiction (For those who know what that is)
Writer: Anti-Storm

TL;DR: The MC is pretty much a standard "system" user, and possesses Liam Sera Banfield from "I'm the Evil Lord of an Intergalactic Empire!" while trying to survive in the Honkai verse.