The KV-5 is a cancelled heavy tank project. It was developed at the Leningrad factory but the German siege of Leningrad halted it from reaching the prototype stage. It's design fell out of favor and the project was cancelled. It was to be armed with an 107mm main gun in a large rotating turret, have 150-180mm of armor, and was estimated to weigh close to 100 tons.
The KV-5 is currently the only tank in the Russian experimental line. It plays in matches with tier V-VII WWII tanks. It has more health than Tier VII tanks meaning it has incredibly thick armor causing it to take less damage. The difference between it and the Maus is that the armor isn't quite as thick on all sides so the back is a weak spot and also the front turrets. The hull is very bouncy to compensate a little. The gun is powerful being able to do large amounts of damage to lesser tanks though it is weaker than the gun on the Maus, T28 and E100. Avoid letting lower tier tanks get in close range where they can circle you. Don't let the slow speed confuse you since this has a fast rotating turret though the the hull still turns slow. Best to lend fire support to your team but try to have your teammates cover your flanks. Head to head a Maus or T28 will tear this apart but it can outmanuever them so use your speed to get in a better position. Hull down is this tanks strong point where the weaker hull isn't exposed.