is there any way to decrese world level?

[timber mango]

Yes use the command, it is in the handbook

All commands are both in the handbook and in /help so be sure to give it a read

Or if you read the wiki (you had to in order to verify) or the usage in game you will be glad to find that the command can be greatly simplified

No

Fetter is friendship

/prop wl x is the shorthand, but do be sure to read the wiki and handbook still

That's fine the wiki and handbook aren't going anywhere, reading it first is so that you don't have to ask "is this a command" and can instead remember that there was such a command

even if you don't remember what the command was, you can just go and look