The second season of Sekai Saikou no Ansatsusha, Isekai Kizoku ni Tensei suru.
PrequelThe World's Finest Assassin Gets Reincarnated in Another World as an AristocratTV · 2021
Alternative versionThe World's Finest Assassin Gets Reincarnated in Another World as an AristocratManga · opens AniList
SourceThe World's Finest Assassin Gets Reincarnated in Another World as an AristocratNovel · opens AniList