Papyrus as Cirno: both generally affibly boastful/etc, prone to taken lightly until the moment it's clear it's not so harmless. (Cirno's Icicle fall normal and Papyrus's Blue attack)
Frisk as Reimu: The protagonist, dodging bullet hell, ending things peacefully.
Sans a Yukari: Powerful but lazy, but threaten things enough and you'll have a bad time (to the point where Yukari starts breaking the game's rules like Sans)
Papyrus as Cirno: both generally affibly boastful/etc, prone to taken lightly until the moment it's clear it's not so dangerous.
Frisk as Reimu: The protagonist, dodging bullet hell, ending things peacefully.
Sans a Yukari: Powerful but lazy, but threaten things enough and you'll have a bad time (to the point where Yukari starts breaking the game's rules like Sans)
Not to mention Yukari's the youkai of borders and is shown by fandom to be medium-aware, and can transport herself between any of them. Sans is also aware of the RPG medium he's on, and is perfectly capable of calling you out on your saves, loads, deaths, and actions throughout the game. He's aware of the game's borders.
