The "part2" in the name means this file is only one piece of a larger set. You cannot extract the data without having "part1" and any subsequent parts in the same folder.
Because this build arrived late in the game's lifecycle (nearly three years after its initial 2020 launch), it focused on technical stability and compatibility rather than adding new characters like Midnight or Present Mic, who were added in earlier patches. my-hero-ones-justice-2-build-10289159-part2-rar
Official updates are typically delivered directly through the Steam client or console stores. If this file was obtained from a third-party site, it is likely a "repack" or unofficial distribution. Always ensure your source is reputable to avoid malware. MY HERO ONE'S JUSTICE 2 Patches and Updates - SteamDB The "part2" in the name means this file