The of Kadokawa has a trailer for an official crossover of KonoSuba, Overlord, Re:Zero & Youjo Senki (Saga of Tanya the Evil). : r/Konosuba

I feel like the Overlord community is the only one who appreciates Isekai Quartet : r/overlord

145 best Kadokawa images on Pholder Anime Figures, Konosuba and Re Zero

Konosuba,' 'Overlord' Anime Crossover Reveals New Poster, Release Date

Isekai Quartet: Filme estreia em junho no Japão

ISEKAI QUARTET KonoSuba Teaser

How would you rank the Isekai Quartet anime (Re: Zero, Konosuba, Overlord, Tanya The Evil, and Shield Hero)? - Quora

Justice is served? No bully flatchair please. [Isekai Quartet] : r/overlord

ISEKAI QUARTET KonoSuba Teaser

New Isekai Quartet Anime Project Crosses Over Overlord, Re:Zero, Tanya, Konosuba Franchises - News - Anime News Network

Crossover-Anime zu Re:ZERO, Overlord, KonoSuba und Tanya angekündigt