So apparently the Ancient Kingdom 900 years ago was arguably more advanced than current day and age Egghead island. Vegapunk is your average Ancient Kingdom scientist and is still looking for answers regarding trivial issues.
On the other hand 900+ years ago someone forged Uranus, a weapon capable of nuking islands. Im recently utilized Uranus and instantly annihilated Lulusia Kingdom with a rain of lasers. Not a trace of the island was left following the attack, and the Five Elders proclaimed that the kingdom had never existed to begin with.
16 light beams were fired simultaneously that completely erased Lulusia
Kizaru while directing this casual attack at fodder nuked a mangrove tree
Here’s a different perspective for the size of these things:
If this casual Kizaru beam was fired 16 times simultaneously it can easily amass such fire power, arguably even far stronger.