For someone who knows of the game, the hero is surprisingly naive and somewhat agreeable.
Ashnold is pretty sure that Yuri is someone like him, a fan transported into the world of the game. It seems reasonable to assume that Yuri recognizes that same trait in Ashnold, and that gives them a common ground that the hero and tutorial boss don't normally have.
In a way, they are already comrades that love this game and have memorized its bugs and quirks and tricks and random offscreen details. There's a fair chance they knew each other in their previous world from forum posts or twitter threads or whatever, though they have no way of knowing without a much more honest discussion between the two.
xXx_DemonGamer666_xXx and YuriFan69 are gonna get along like a house on fire when they do have that discussion. Probably not until they set that house on fire, though.