setcell "koe",18,24,24,18,cell_walkable,0; //not walkable
setcell "koe",18,24,24,18,cell_walkable,1; //becomes walkable
Set cell_walkable to 1 only when the boss dies.
OnInit:
setcell "koe",18,24,24,18,cell_walkable,0;
end;
OnMVPDead:
setcell "koe",18,24,24,18,cell_walkable,1;
end;
Just spawn monster
monster "this",0,0,"Poring",1002,1,strnpcinfo(0)+"::OnMVPDead";
So when they kill that monster, it will trigger the OnMVPDead event and it will make the cell walkable.