Honestly niinim is that guy. One of the denizens of NA soloq for sure. He's very good at twitch, and one thing he'll do when losing lane, like if twitch+support get 2v2 killed bot, is simply abandon the bottom lane and gank top. Then go top again. Then mid. I mean really abandon bot. He streams (https://www.twitch.tv/niinim) so maybe he's explained roaming but idk I haven't watched, but I think it's partially anger at teammates, but also partially twitch if behind really struggles to farm bot but is great at randomly showing up to gank other lanes. From behind twitch can't all in and is just short ranged and contested on every cs and it seems miserable. Whereas his gank is surprising and at least makes something happen.

He also plays draven/karthus. Idk why twitch/draven/karthus feels like such a common terrorist adc trio (maybe because they all just try to kill people...or they're all pretty strong right now). I think he also fairly uniquely goes duskblade draven.