Assassins and turrets

Turrets can be taken down with Shurikens easily. Here's how.

Level 3 Cloak
Gold RoF
Silver Reload Speed
Bronze Ammo

You can spam a ton of criticals, overall dealing more damage then the Support can heal quickly (post-nerf). With the faster reload, there is no reload time on the Shurikens, and you can fire another full clip of criticals. Fire a few full clips into the Turret of any kind, and it goes down.

Standing a safe distance away of course. I've wrecked bases WITHOUT being cheap and juicing by using this tactic. It's very effective if you use it properly.