Law's attack:
Hakai:
Bro, there are levels in DC, I mean, Hakai is also an island level attack but look at the crater which it caused, meanwhile Law's attack caused a freaking abyss whose actual depth cannot be seen - but is actually deep enough for Law to feel save to use his shockwave.
Don't just look at the surface damage, then you'll understand why this attack is at least island level.