When i use obs to record my runs my mouse dissapears. i have all legal mods installed for speedrunning. idk which one causes this issue.

Have you tried to troubleshoot with other on-screen recording software to see if this is OBS-related only? Any info on the OS and hardware?

If you're using "game capture" for the source, check that the mouse cursor showing option is enabled in properties.

window capture and display capture also have that checkbox

Oh, yeah, that's an obvious one, always forget to go for those more simpler answers :D