Garp's attack, although decent and capable of splitting the skull of the island, upon closer observation, is not as large as I initially thought. It is smaller than Onigashima's skull, but even so, Garp's attack couldn't even knock out Pizarro. This raises a question: Does Pizarro have greater endurance than Luffy after Udon (1009 Luffy)? I would say no. Therefore, Garp's attack power is overestimated, and Ragnarok > Garp's attack. The good thing is that Ragnarok doesn't need to be flashy to be effective.