However, there are a variety of counters to this tactic. GDI trains its Grenadier squads exceptionally well; they are capable of killing any infantry squad that garrisons itself by lobbing grenades through the windows if they can get to it. Similarly, Nod's Flame tanks, Avatars Flamethrower, Purifiers and Black Hand troopers are well trained in urban combat scenarios, and their flamethrowers can quickly incinerate every room in the building, along with the helpless soldiers inside. The Marked of Kane lacks flame weaponry, but their Tiberium troopers are able to fill in the same role with its tiberium gun which will spray Tiberium gas to poison every room in the building. During the Scrin invasion, Buzzers have been known to enter structures and shred troops holed up inside. Corrupters can