[Riyu]

Just report the account to a staff member.

[Riyu]

I'm talking about big bug here.

you can change your name to anybody. so i could change name to Omniscent or something like that. 
Fck this shit.

Delete this option to change usernames. <.<

You can't actually change your username to Omniscient lol.

He doesn't need to delete the option to change usernames. There are other ways to fix the issue.

(not a bug either, invisible characters are just allowed)

[Riyu]

alright

found the guy's facebook and instagram, don't know what to do with it though

It's most likely a compromised account.