1) Clone bug. A friend playing a guardian had a clone of his character appear after fighting a mesmer. (image below).
2) Wall name bug. A wall of an upgraded ennemy tower appeared as a simple non-upgraded wall. It clearly had the hp of an upgraded wall. I believe the wall was indeed upgraded in the tower (considering the amount of supply inside the tower), but the “reinforced wall” name only appeared as “wall”.
3) Teleportation of a warrior. That may be a cheat or something, but I saw an ennemy war teleport behing our siege weapons, throw a grenade, than teleport back on wall. I and some friend had teleportation bugs recently so I’m not sure about bug or cheat here
