After three playthroughs I'm fairly comfortable in crowning Dark Souls III as the easiest game in the series, but that doesn't mean it's not tougher than most action titles currently on the market.
There were several zones and boss fights (mostly zones this time) that I struggled with, and one of them was Pontiff Sulyvahn, which I encountered a little too early for my own good. YouTuber neptunusequester on the other hand, figured out a way to stomp him into oblivion in one shot, in what they call the "1HKO" (one hit KO) challenge.
In essence, they buff the hell out of their character, who's using a massively powerful two-handed weapon, then riposte the boss. Doing huge riposte damage is a Souls staple for boss runs, but the way it's done here, presumably with tons of homework and number crunching in preparation, is impressive.