Thanks @V3ct0r, I searched for some topics and found that 3D Max tool (FatImporter?), but it seems that its outdated and doesnt to work to do things such as converting .obj to .lgo, to do things like create new mobs or equipment or recreate old ones and add them back into the game without much bugs.
I also found this: https://ufile.io/wyh13zl2
I will gladly pay for a updated version, if anyone wants to offer his time and skills