Lulusia, as shown in this chapter is a particularly small island/country (unless the castle is some gigantic 50 mile building).It's also probably true that it took a while to prepare this attack (at least two/three weeks).
So, we witnessed a small island/country DC with week long preparation time, when Whitebeard could sink an island with one quake punch.Even when we're not taking into account the most destructive DF in the verse, Aokiji and Akainu have shown that level of DC in Punk Hazard.
Ace and Blackbeard clash was not much smaller and they weren't even top tiers.Even Enel's Raigou could have had similar DC.
Not saying it didn't look cool, but I'd expect something more than this from an Ancient Weapon.Still an insane panel.
So, we witnessed a small island/country DC with week long preparation time, when Whitebeard could sink an island with one quake punch.Even when we're not taking into account the most destructive DF in the verse, Aokiji and Akainu have shown that level of DC in Punk Hazard.
Ace and Blackbeard clash was not much smaller and they weren't even top tiers.Even Enel's Raigou could have had similar DC.
Not saying it didn't look cool, but I'd expect something more than this from an Ancient Weapon.Still an insane panel.