Feat[]
Miss Doublefinger uses her Sea Urchin Stinger to bore a perfectly circular hole straight through a wall. We don't have an official height for Miss Doublefinger but she's slightly taller than Nami (169 cm) and she's slightly off-panel on the page used to get the diameter of the hole, so I'm going to estimate her height on-panel to be 169 cm for the purpose of this calc.
Since Nami comments that the wall is scorched and there might be dust/steam rising from the hole, I'm going to include a value for vaporization as well as pulverization to get the high-end and low-end of the feat.
Calc[]
Miss Doublefinger's Height = 269.1 pixels = 169 cm
Hole's Diameter = 252 pixels = 158.26 cm
Hole's Diameter = 149 pixels = 158.26 cm
Hole's Depth = 15.5 pixels = 16.46 cm
Volume = 324000 cm^3
Pulverization value = 214.35
Vaporization value = 25700
Energy (p) = 324000 * 214.35 = 69449400 joules
Energy (v) = 324000 * 25700 = 8326800000 joules
Result[]
Pulverization Result = 0.0166 tons - [Small Building level]
Vaporization Result = 1.99 tons - [Building level+]
Welp, she'd just barely qualify to be High 8-C overall seeing as she can amp up her strength with acupuncture and the result is so close to the threshold for High 8-C.