Is using an unob item in pvp bannable?

[Geolindrag (Geo)]

Yea it is bannable, Regardless if was obtained without a modified client :

@system

#2 Exploits

An exploit is unintended behaviour of the game that can be done without using third-party modifications (as that would be considered violation of S5#1). This also includes unintended behaviour of the server. The use of exploits is forbidden and punishable by a ban. It will be up to the discretion of staff to provide a warning instead, where an exploit has a minor impact.