@EDIT
I edited and was the easiest thing in the world. for those who want to make a system Anti -Run PvP edit this
Search src/map/skill.c and find:
case TF_BACKSLIDING:
clif->skill_nodamage(src,bl,skill_id,skill_lv,1);
skill->blown(src,bl,skill->get_blewcount(skill_id,skill_lv),unit->getdir(bl),0);
clif->fixpos(bl);
break;
and add after clif->fixpos(bl);
case TF_BACKSLIDING:
clif->skill_nodamage(src,bl,skill_id,skill_lv,1);
skill->blown(src,bl,skill->get_blewcount(skill_id,skill_lv),unit->getdir(bl),0);
clif->fixpos(bl);
sd->canlog_tick = timer->gettick();
break;
So you can no longer logout when using this skill.