As the player has a larger field of view than most of the tanks, they can attack them before they even see the player. This works very well against slow tanks, as the player can attack and retreat without ever being spotted.
When fighting a tank as an Assassin, players always have the advantage of a high Bullet Penetration and Speed, making destroying tanks easy; also, since players have such a large FoV, they can see stray Bullets and dodge them more easily or even spot unsuspecting players and go in for the kill. However, those stat advantages may be nullified should enemies have a high DPS (Damage Per Second). An Assassin's Bullet may be able to get past a few of the enemy’s Bullets but probably not through a whole stream of them. Players should keep changing their position to get a better angle, deal more damage, and avoid detection.
Assassins are surprisingly viable for killing Smasher branches, as players can shoot at the tank while retreating backwards. Slow rammers will not be able to catch up and will take large amounts of damage from the Assassin's Bullets.
If a tank charges at an Assassin, players should shoot while retreating since the Assassin is stronger at a long range. Once enemies get close to the player, they will be able to damage Assassins easily. Players should keep shooting at them, and try their best to predict their movements in order to inflict as much damage as possible to the target (e.g. a Body Damage Booster build).
Since it has a low rate of fire, players should try not to be attacked by two or more tanks; players should also use their upgraded Field of View to locate opponent's whereabouts and avoid them as much as possible.
Rammers could kill an Assassin, because of the Assassin's slow Speed and low Recoil; if the Rammer's stats are high on Movement Speed, the Assassin can't escape.
The Destroyer branch is effective as it can destroy the Assassin's bullets and kill it. But players should be careful, since the Assassin's bullets can travel very fast and reach far past the large bullet, so players should dodge any bullets that make it past.
The Assassin is one of the original classes in the game. This tank has always been in Diep.io since its public release.
The Assassin's upgrade button is blue, even though it was added after Overseer was added. If the button was true to its time added, like other tanks, then its upgrade button would be green, and the Overseer's upgrade button would be blue.
Dingbat1911's fan-made version of Skimmer upgraded from Assassin instead of Destroyer.
The fan-made version can be found here (Top row, far right).