From WoT Forum

The KV-2 with the "Sheitan tube" can, of course, kill with one shot any tank at a level below it, but at the same time the recharge of this "tube" is more than 20 seconds. During this time, you can not just disassemble the completely defenseless KV-2, but have time to dance around it and sing to him “Goodbye, our affectionate Misha.” And such examples are many. If such an enemy has just hit you and failed to hit, then you have a lot of time to go out, target, crush him a trunk or fur, shoot a second time, and again to hide behind the corner, disgustingly crazed.