Yeah there's a lot of "silliness" going on and if you look at from feat perspective then even the supporting cast are ridiculously durable and insane. Can't remember her best friend's name but I'm thinking of the scene where she took like thousands of tennis balls to the face or when Matoi got obliterated by the boxing guy before getting her sangetsu outfit. May have spelled that wrong. I think I recall a time when Satsuki herself lightly tapped Matoi and sent her flying through the stands as well. In no way are the KLK weak, I just don't fully remember how they would compare to Dante due to not being in the DMC franchise for like 10 years.
Well in episode 2 Ryuuko cuts about a hundred tennis balls into five pieces in under a second, maybe even more considering they explode into shreds afterwards. And yeah, Satsuki taps Ryuuko and sends her flying across the school and through a wall, plus later in the fight she kicks her and creates a 20 meter tall crater in the wall behind her from the sheer impact. And then when they clash swords their blows are shattering the ground and creating huge explosions of force that send hundreds of people flying.
if we're talking about DMC4 Dante here, then while he and this Satsuki seem to be evenly matched in durability and strength (though Dante appears to edge her out slightly in the latter), Satsuki is supposed to be like around Mach 50 from what I've heard. Dante hasn't shown himself to be that fast to my recollection.... though DT might make a difference.