Hey, I just wanted to ask for a multiplayer category. What is your opinion about that? I dont find any category with multiplayers.

Multiplayer speedruns are looked down upon by site staff, and are advised to not be added. If you are referring to co-operative speedruns, I personally would be very interested in a co-op acrophobia speedrun category, as well as maybe a hunter% and heroic.

If you are referring to standard difficulties, and their respective co-op categories, they can be found here:

https://haloruns.com/records/hce/co-op