It has come to my attention that we solely used Marisa's "Shoot the Moon" attack as lightspeed because it was called "light" once.
However, it seems like Okuu's "Hell's Artifical Sun" or "Subterranean Sun" is a more valid source of light.
"An artificial sun, bombarding you with photons."
"It must be heavy, to draw you in like that. Light has no problem escaping its gravity, though."
"The sun of the underground, sucking you in as it shines on you."
"The sun is meant to be above ground. Dodge its rays as you fight to go back there."
Not only is an actual mini-sun a much more credible as a source of light than Marisa's magic, but we have multiple statement relating it to light such as photon or the capacity of escaping the event horizon.
However, the very same attack was also featured in Hisoutensoku. This would disprove all the calcs using KE, which includes 6-C Cirno and Low 6-B Suwako.
So I have to re-do some calcs and do some more of them.
First, the light itself.
The bullet of light moved at 29 pixels the frame. Pretty simple. It will be useful to compare to other characters' feats.
Nearly all of Cirno's ice attacks are faster than this, so I'll have to use her normal down strong attack here.
In a frame it moved 25 pixels. Which means it's 0.8620689655172414 times the speed of light or 258442241.3793103510302 m/s.
For the mass we will have to compare to Cirno. She is 82 pixels tall here. While the ball of ice is 101 pixels. So the ball is 1.2317073170731707 times taller. I already covered that Cirno is 1.15 meters tall in my previous blog, so via math, this ball has a diameter of 1.416463414634146305 meters.
Since it's a sphere, the volume would be 1.49 m3, so 1490000 cm3. Ice has a density of 0.92 g/cm, so the mass would be 1370800 grams or 1370,8 kg.
Via Relativity (I think it's alright to use it here?) the mass would be 1.9732000705753383 larger or 2704.86265674467374164 kg.
Using the above speed, we get... 90332123612408180000 joules or Island level. Phew, no changes there.
Now for speed.
In her Ice Sword move, she moves, well, fast. 124 pixels here. While light moves at 29 pixels. So 4.2758620689655172 times FTL.. This scales to nearly everyone in all speeds.
In this one, Sakuya does huge slashes in a frame or two. The length of all the slashes combined is 2221 pixels. Since it was done by the two arms however I'm guessing it will be divided by two, or 1110.5 pixels. Divdied by 25 for light, we have 44.42 times the speed of light. I didn't take into account the curvature or the bits not on the screen so it's probably a bit lowballed. The whole calc is pretty rough but the result shouldn't change much.
In reactions and combat speed, this scales to Sakuya, Patchouli, Remi, Flandre, Marisa, Reimu, Kaguya, Mokou, Byakuren, Miko, Kanako, Suwako, Suika, Yuugi, Aya, Youmu, Yukari, Yorihime and Toyohime, Yatagarasu, Dragon God, Junko, Hecatia, Clownpiece, Yuyuko and possibly some others I frogot.
Here, Aya quickly dashes in the form of these red things. The Black one travels the whole screen in the second screen so it's represented by the measure line being extended. The blue ones are done in a single frame rather than two, so they'd get doubled since they were done in half the time.
Blue ones get 468 together, so 936 because time. Including the black one, it's 1331 pixels, so 53.24 times the speed of light. Scales to Youmu and the god tiers. Note that I didn't take into account that the screen zoomed out, because lazyness, so it could be higher. Not enough to reach a tier above tho.
So here Youmu does a view ultrabazzytrillions hits in a frame. This is a cube so there is 4 horizontal black line. There is also two diagonal line and two red diagonal too.
319 x 4 = 1276
407 x 2 = 814
293 x 2 = 586
This gives together 2676. Two times since this is all done in a single frame. 5352 pixels. So 214.08 times the speed of light. Massively FTL for her.
This only really applies to Youmu and the God tier.