(I asked a friend who can read Japanese to have a look at this, and they confirmed this is more or less accurate)
An Ashtanga exploding shakes the entire Anti-Spiral pocket universe, which Super Galaxy Dai-Gurren withstands with it's Spiral Shields. Looking back at my old Captain Harlock Noo artefact calc for help here, calculating the energy to shake the planet then applying inverse-square law. The minimum magnitude for an earthquake to be felt for the average person is magnitude 3 (though some extra sensetive people can feel magnitude 2.5 earthquakes).
E = 3720000000000/10,000
= 372000000 joules
Now for the surface area of the area affected, that being the observable Universe (46,600,000,000 lightyears, or 4.40870040022e+26m).
A = 4πr^2
= 4 X π X 46,600,000,000^2
= 2.72886278e22LY^2
= 2.44248012179300965e+54m^3
Finally for our energy, which we'll find using inverse-square law.
I = S/4pa
372000000 = S/(4 X π X 4.40870040022e+26^2)
= 372000000 X (4 X π X 4.40870040022e+26^2)
= 9.08602604e62/10^44
= 9.08602604 EXAFOE
Final Results
Ashtanga explodes = 9.086 EXAFOE